3. Taking of evidence

Catchword:

Hearing a witness in first instance proceedings by videoconference allowed sufficient interaction between the deciding body, the parties and the witness. Albeit a part of the witness' body language was not visible to the participants, this did not amount to an infringement of the parties' right to be heard since the judgement on the witness' credibility was mainly based on the conclusiveness of his/her testimony and the absence of contradictions within the witness' own testimony, between the testimonies of several witnesses and/or contradictions between the witness' testimony and information derivable from supporting documents (reasons, point 2).

Abstract

In T 2517/22, in support of their argument of lack of inventive step, appellant 2 (opponent) had submitted documents D2 (operating manual) and D2a, which was the affidavit of an employee of appellant 2, Mr R.

Already in the notice of opposition and again in their reply, after the patentee had put into question the probative value of the affidavit D2a, appellant 2 had offered Mr R as a witness. In the annex to the first summons, the opposition division considered D2a to be sufficient evidence for public availability of D2 and did not summon Mr R as witness. In the annex to the second summons, discussion of novelty over D2 was envisaged for the oral proceedings. The opposition division changed its mind however and announced, after discussion of public availability of D2 during the second oral proceedings, that D2 was not part of the prior art albeit without taking into account the previous offer to hear a witness on the topic.

In the board's view, the statements in the affidavit D2a represented facts which were a priori of high relevance for the establishment of whether or not D2 was part of the prior art in the sense of Art. 54(2) EPC, and therefore of high relevance for the outcome of the opposition proceedings. An offer to hear the undersigned of the affidavit D2a as a witness represented a further relevant and appropriate offer of evidence for the facts. The board stated it was a party's choice to present whatever means of evidence it considered to be suitable and it was an opposition division's duty to take its decision on the basis of all the relevant evidence actually available rather than to expect the presentation of more preferred pieces of documentary evidence, and to speculate on the reasons for and draw conclusions from their absence. The opposition division was of course free to evaluate any evidence provided by a party, but this freedom could not be used to disregard evidence that had been offered, and which might turn out to be decisive for a case, in particular not with the argument that some better evidence would have been expected.

Instead of accepting the evidence offered by appellant 2, the opposition division appeared to have based its decision on general assumptions made on the capability of persons to recollect events after a certain time period (15 years) and specific assumptions made on the witness's personal capability, knowledge and experience, thus implicitly on assumptions made on the veracity of his statements and on his credibility. By making these assumptions without hearing the offered witness person, the opposition division had in fact assessed evidence without examining it.

According to the respondent (patent proprietor), the offer of Mr R as a witness was not substantiated. For the board, affidavit D2a appeared to contain the factual information relevant for the outcome of the case. Before the oral proceedings, the opposition division had not shared the respondent's concerns about the veracity of D2a. The board stated that appellant 2 did not have to address these concerns and had no obligation to announce in their offer how exactly the witness would be able to corroborate his own statements, e.g. by answering in advance hypothetical questions that might possibly arise. Such questions would normally be asked during witness hearings in order to assess the credibility of the witness and the exactness of their memory, which is one of the main purposes of the hearing. A sufficiently exact recollection of various events 15 years later should not have been denied beforehand.

Appellant 2 requested that the decision be set aside due to a violation of their right to be heard and to remit the case. The board concluded that the failure to consider appellant's 2 offer to hear a witness on the public availability of D2 constituted a substantial procedural violation of the right to be heard. The decision of the opposition division to reject both oppositions was set aside in order to allow re-examination of the public availability of D2 taking into account all the evidence admissibly submitted by appellant 2.

Abstract

In T 778/21 (laundry appliance), the opposition division concluded inter alia that the subject-matter of claim 1 of the patent as granted was not new in view of both document E2 and the prior use (PU) relating to a washing machine. Both parties appealed. The opponent alleged that the sale of the prior use PU washing machine as detailed on the invoice PU1 and the related affidavits of Mr N. (PU3) and Mr E. (PU2) sufficed for proving that the machine was publicly available. Serial numbers were unique, so the indication of the serial number of the prior use machine allowed a definitive identification of the machine. Thus, in the opponent's view, the inspection of the machine or the hearing of witnesses as requested by the proprietor was not necessary. The errors in the opponent's grounds of appeal associated with the model number for the prior use PU were to be seen as clerical errors. The proprietor inter alia submitted that in view of the doubts presented already in the opposition proceedings, an inspection of the machine with serial number C21850524 and the hearing of witnesses would have been necessary for verification.

The board first dealt in detail with several issues in relation to RPBA and late filed submissions at different stages, eventually most not admitted. On a particular late submission, the board did not accept the opponent's argument that documents filed during the written stage of the opposition proceedings should generally be included in the appeal by default. Regarding the opponent's reaction to the preliminary opinion of the board, in which the opponent explained that the incorrect association of model number WFW97HEXW2 with serial number C21850524 was a clerical mistake, the board found that exceptional circumstances existed that in its view justified admitting the opponent's explanation.

Concerning the general principles for assessing an alleged prior use, the board set out four steps that should generally be made (detailed in the Reasons). Steps 1 to 3 consisted in the examination of the substantiation of the prior use, establishing the evidence offered by the opponent as bearing the burden of proof and the evaluation of the entire evidence offered by the opponent. Depending on the outcome of this evaluation, step 4 could vary (three variants) depending on whether or not the opponent's evidence on file confirmed the alleged facts, or if doubts remained, and whether the opponent did (first variant) or did not (second variant) request an inspection or hearing of witnesses (see the detailed Reasons as to the consequences). If, in the third variant, the opponent's evidence confirmed the prior use, the (counter) evidence offered by the patent proprietor would become relevant and would need to be considered. If assertions made in an affidavit or in any other witness declaration remained contested, a request from a party to hear the (available) witness would have to be granted. The board made reference to G 2/21 (points 41, 42, 44 of the Reasons) and to T 474/04.

In case T 778/21, the board applied these general principles for assessing the alleged prior use. Steps 1 to 3 of the assessment were fulfilled. Step 4 concerned the third variant, therefore the proprietor's request for an inspection of the washing machine and for hearing the authors of the affidavits as witnesses needed to be granted. Since the alleged instance of prior use concerned a specific machine to which the proprietor had no access, the applicable standard of proof was either "beyond all reasonable doubt" (T 97/94) or that the deciding body had to be convinced with a sufficient degree of certainty (T 1138/20, T 545/08). Thus, based on the submissions and evidence on file, the board found that the opponent had substantiated that the machine of the prior use was made available to the public and had provided evidence confirming the related facts. Based on the evidence on file, all features of claim 1 were seen to be known from the prior use. Therefore, the patent proprietor's request for taking (counter) evidence (step 4, third variant) needed to be considered. A final conclusion on whether all relevant aspects of the prior use, including public availability, were proven beyond reasonable doubt, could only be drawn after considering the evidence requested to be considered by the proprietor, i.e. after inspecting the machine and hearing the witnesses. The case was remitted to first instance for further prosecution.