b) Evaluation of evidence by the department of first instance – review  

i) Applicable law and recent discussion in the case law

Questions arise especially with regard to witness testimonies because the boards do not necessarily rehear witnesses. This has led to questions about the scope of the boards' power to review facts established at first instance, particularly those arrived at after hearing witnesses. That is why these questions are addressed under the present section.

The applicable law now seems to have been established by T 1138/20 (especially points 1.2.4 and 1.2.6 of the Reasons), which largely endorsed the principles set out in T 42/19 and which dealt not only with evidence given by witnesses but with documentary evidence too (see, for example, point 1.3.4(c) of the Reasons).

On the boards' competence, T 1138/20 states, in particular, that the boards of appeal constitute the first and final judicial instance and thus the only judicial body to establish both facts and law in proceedings before the EPO. As such, the boards have the power, at any stage of the appeal proceedings, to establish the relevant facts of the case before them and thereby substitute the findings of fact made by the departments of first instance. However, the boards have no obligation to establish de novo facts already established by the departments of first instance (see T 42/19, point 3.3 of the Reasons). Indeed, neither the EPC nor any decision of the Enlarged Board of Appeal limits the boards' competence to establish the facts. And the boards' power to establish the relevant facts of the case before them is not limited to what the parties have provided or what the first-instance department has established.

As earlier case law shows, the scope of the boards' competence had already begun to be expressly discussed in a series of still relatively recent decisions, starting with T 1418/17, which the board in T 1604/16 then cited but did not follow, holding instead that boards had the power to review contested decisions in full, including not only the points of law but also the facts. The later decision in T 42/19 not only confirmed the principles set out in T 1604/16 but appeared also to reconcile them with those in T 1418/17, which was considered to provide valuable guidance (namely a list of "typical scenarios"). T 423/22 (witness hearing by videoconference) endorsed the approach taken in T 42/19.

The board in T 1138/20 held that the list in T 1418/17 was not exhaustive: since the boards had full competence to review findings of fact, there was no reason a board should be limited to those criteria in its review. It observed that there were other situations too, noting, for instance, that a finding of fact could also be reversed if it was not corroborated by the evidence on file.

ii) Reporting more about the reasons regarding different decisions from T 42/19

The board in T 42/19 considered the list drawn up by the board in T 1418/17 of when to review evidence to be valuable guidance, while the board in T 1138/20 likewise found the three typical scenarios identified there to be helpful. However, as this list was reused, for example in T 42/19, there is no need to report T 1418/17 and its reasoning below. As already found in T 1138/20, the list is not exhaustive (point 1.2.6 of the Reasons, referring to T 1604/16 and T 42/19).

The board in T 42/19 summarised the scope of the boards' power to review a first-instance decision as regards the evaluation of evidence as follows in the Catchword:

"1. A board's power to review appealed decisions is not limited to points of law but extends to points of facts (in agreement with T 1604/16).

2. However, it is settled case law that a board is not obliged to take all the evidence anew and that parties do not have the right to have the taking of evidence repeated at their request before the board.

3. The principle of free evaluation of evidence, meaning that there are no firm rules on the probative value of the various types of evidence but that the deciding body is entrusted with weighing up all the evidence and basing its decision on what it is then satisfied has been established, implies a degree of freedom comparable to the one referred to by the Enlarged Board of Appeal in decision G 7/93, Reasons 2.6."

(On the obiter dictum from G 7/93 cited in T 42/19, see, however, T 1138/20, point 1.2.4(a) of the Reasons, which states that a board's review of a fact-finding process should not be conflated with the review of discretionary decisions within the meaning of G 7/93, Reasons 2.6)

"4. Thus, it is wise to similarly respect this freedom, especially when taking into account that a board, except when only reviewing documentary evidence, does not have the same first-hand impression of the probative value of a means of evidence as a department of first instance that has itself heard a witness or expert or inspected an object.

5. Although the board is not limited in its decision, it normally seems useful to apply the test set out in decision T 1418/17, Reasons 1.3: Unless the law has been misapplied (e.g. application of the wrong standard of proof), a board of appeal should overrule a department of first instance's evaluation of evidence and replace it with its own only if it is apparent from that department's evaluation that it: (i) disregarded essential points, (ii) also considered irrelevant matters or (iii) violated the laws of thought, for instance in the form of logical errors and contradictions in its reasoning.

6. The evaluation of evidence only refers to establishing whether an alleged fact has been proven to the satisfaction of the deciding body. The discretion-like freedom is restricted to this question and does not extend to the further question of how the established facts are to be interpreted and what the legal consequences are (see Reasons 3.2 to 3.6)."

In T 42/19 the appellant (opponent) had requested a reversal of the opposition division's decision that an alleged public prior use of an insulin injection device marked named GensuPen had not been sufficiently proven. In its reasons, the board recalled the principles set out in the Catchword quoted above and stated that the boards usually just reviewed the way in which the evidence had been taken by the departments of first instance and, where they did not find any deficiencies, applied the law on the basis of the facts found in the decisions. A board, being a deciding body as well, was also entrusted with weighing up evidence under the principle of free evaluation of evidence. As a consequence, it could not be excluded that a board might come to a different conclusion than the body that had issued the impugned decision. But being under the obligation to give reasons for its decision, the board had to be able to convincingly demonstrate where the competent division had erred. The test set out in T 1418/17 gave valuable guidance in this respect. In the case in hand, none of the circumstances which would justify a review could be identified in the department of first instance's reasoning. In particular, the balance of probabilities had been the correct standard of proof. As regards the witness Ms S., relevant information was completely missing (for example, in what capacity she had accessed the consultation room of the medical centre, the precise circumstances under which she had obtained the GensuPen, whether she was a member of the public and why she had on the same day written a declaration that was used six years later). This cast a shadow on the plausibility of her statement and justified the opposition division's finding that, even under the lower standard of proof of the balance of probabilities, the public prior use had not been sufficiently proven, because the circumstances had not been fully and clearly specified. This lack of factual basis had not substantially changed with the new submissions in the appeal proceedings. And without this fundamental information, it was irrelevant whether the respondent (proprietor) bore the burden of proving that certain persons, such as hospital personnel or patients in a study, had been bound by a confidentiality agreement. The board did not see any reason to overrule the decision concerning the alleged prior use of GensuPen and therefore confirmed the opposition division's conclusion. In exercise of the discretion provided by Art. 12(4) RPBA 2007, the board further decided to disregard the request submitted by the appellant on appeal that another witness be heard to fill in the gaps identified by the opposition division, since doubts and objections in this respect had already been raised by the respondent (proprietor) during the written opposition proceedings.

Details of the decision in T 1138/20 have already been reported above, and so this passage deals with just a few additional aspects. The board in T 1138/20 stated that if the findings of fact of the departments of first instance relied on documents, the boards regularly made their own assessment of the evidence. In the case of oral evidence given by a party, a witness or an expert (Art. 117(1)(a), (d), (e) EPC) or an inspection (Art. 117(1)(f) EPC), the boards would normally not assess the evidence de novo by, for example, rehearing the witness. In such a situation, the department that had heard the witness was better placed to determine the probative value of the evidence given, in particular the credibility of the witness and the reliability of the testimony (i.e. its accuracy, e.g. how accurately the witness remembered and recounted the events). The boards could then defer to the first-instance department's evaluation of evidence. The board also stated that for demonstrating an error in the fact-finding process (point 1.2.6 of the Reasons), it would generally not be sufficient to argue on appeal that the evidence on file would have allowed a different conclusion and that this conclusion was equally likely, plausible or reasonable. Rather, in order to show an error, the party had to demonstrate that no body competent to establish the facts and acting in a reasonable way could have come to that conclusion. In such a situation, the contesting party could successfully allege on appeal that the first-instance department had not fulfilled its duty to give reasons for its finding of fact. The party challenging the factual finding could claim an error in the opposition division's reasoning. The board also acknowledged (point 1.3.7 of the Reasons) that a finding of fact could be reversed if the findings of fact of the opposition division were not corroborated by the evidence on file. An example would be that the opposition division relied solely on witness evidence for a fact that the witness could not, or did not claim to, have witnessed. However, that was not what had happened in the case in hand.

iii) Examples of how reviewing findings of fact has been dealt with in other case law

As is illustrated by the decisions reported below the issue of reviewing findings of fact had already arisen in the case law prior to T 42/19.

The board in T 2565/11 overturned the evaluation of evidence made by the department of first instance because the opposition division had erred as regards the underlying facts and failed to give an evaluation that was free of contradictions. The board gave its own evaluation of the evidence regarding the relevant facts. The board also noted that further explanations given by a witness, in order to close a potential gap in the documentary evidence on file, could not be considered per se as new facts. Otherwise, hearing a witness would be meaningless, and evidence provided on the basis of documents would be given a higher evidentiary value than a witness testimony, for which no basis could be found in the EPC. T 2565/11 is cited in T 2398/12 in the context of an object submitted as evidence in support of an allegation of public prior use which had gone missing during the appeal but had already been examined by the opposition division.

The board in T 1476/14 held there was no ground in the case in hand to overturn the opposition division's assessment of the testimony of two witnesses. The credibility of witnesses cannot be impugned because of differences in testimonies relating not to the essentials but to less important aspects of prior use.

In T 1798/14 the opposition division had considered the witness reliable and his answers detailed, credible and consistent overall. The respondent (patent proprietor) had not voiced any concerns either; it had merely disputed that the machine witnesses may have seen comprised all the features of the claim. The board saw no reason to depart from this assessment and to doubt the accuracy of the witness's statements. In T 544/14 the question of evaluating the evidence was again discussed in detail by the board (rehearing the witness necessary but eventually not decisive – alleged public prior use not novelty-destroying).

According to the board in T 621/14 appeal proceedings were not intended as a second opportunity to have evidence heard unless sufficiently substantiated grounds for appeal gave some reason for it. The mere desire for evidence to be evaluated differently did not result in a re-opening before the board of the procedure for taking evidence. The board saw no reason to deviate from the prior art identified by the opposition division through the hearing of witnesses.

In T 1107/12 the board pointed out that the opposition division's evaluation of the testimony had left it in no doubt as to its reliability or the witness's credibility as a person. Its evaluation of the evidence was not otherwise vitiated by any error in law. It was based on the right criteria, could be followed in all respects and did not contain any logical mistakes. It was therefore not open to the board to overrule its findings and re-evaluate the evidence in its place.

In T 804/92 (OJ 1994, 862) the opposition division had, in a communication to the parties, suggested in detail the content of a statement under oath. Such a practice was firmly rejected by the board because it involved the risk of leading witnesses and could seriously undermine the probative value of such statements. This applied to departments at any instance in proceedings before the EPO.

T 1604/16 is a significant decision that both T 42/19 and T 1138/20 cited and endorsed while also reconciling it with T 1418/17. Given that T 42/19 and T 1138/20 have already been reported above, there is no need here to go into the principles and reasoning in T 1604/16 (in particular the reference to Art. 12(2) RPBA 2020), and instead what follows simply reports how the facts of the case were evaluated. The invention in T 1604/16 related to a foldable ramp for loading a wheelchair into a vehicle. The opposition division had based its assessment on E1, E1/1 (with photographs) and the testimony given by a witness (buyer of the vehicle equipped with the ramp). The evidence adduced before the board included documents E1, E1/1 and the minutes of the hearing of the witness at first instance. There were no issues in terms of the witness's credibility (see in general T 474/04). The board did not see any reason why it should limit its review by applying the criteria set out in decision T 1418/17. In the case in hand, in view of several remaining doubts which arose from the content of the minutes, the board held that the evidence produced was insufficient and hence that the opposition division had erred in concluding that the ramp shown in E1/1 formed part of the prior art. See also chapter V.A.3.2.1. "Primary object of the appeal proceedings – Article 12(2) RPBA 2020".

T 1634/17 concerned an ephemeral disclosure (D11). The board could not agree with the opposition division, which had taken "into account the amount and quality of all evidence produced, particularly the reliability of the witness recollections and the high relevance of D11". Neither the amount nor the quality of all this evidence, nor, for that matter, the reliability of the witness recollection at the oral proceedings at first instance, needed to be assessed by the board. Whilst all this evidence might have been used to support, complement, interpret or explain the content of a contemporary written note, none of it was as reliable as such a contemporary note. The fact that none of the declarations on file was a contemporary written note taken at Dr M.'s presentation needed to be taken into account, but the opposition division had not done so. D11 was found not to form part of the state of the art.