4. Late submissions

In T 2734/16 the board held that a new line of attack on inventive step pursued in response to and using the documents submitted by the patent proprietor with its reply to the opposition should not be considered late filed per se. For reasons of "equality of arms", the new attack could be admitted into the opposition proceedings even if the documents ultimately proved no more relevant than other documents. In the case in hand, the patent proprietor had asserted that the large-scale road milling machines illustrated by the examples in the documents submitted with its reply to the opposition formed the closest prior art. In these circumstances, the appellant had to be entitled, with a view to ensuring equality of arms, to take the facts first brought to its attention by the new documents submitted by the opposing party and use them for its own ends in a counterattack relying on them as new arguments against inventive step. Since this counterattack had only become possible once the respondent had submitted these documents in its own defence, the board, having considered all the circumstances, did not deem it appropriate to refuse the new line of attack on the grounds of late filing and irrelevance of the documents on which it was based. See also under chapter V.A.6.4 "State of proceedings – procedural economy – RPBA 2007".

In T 1551/14, during the written proceedings that followed initial oral proceedings before the opposition division, at which four witnesses had been heard, the patent proprietor had filed a new auxiliary request limiting the subject-matter of the two independent claims by a new feature. Having been summoned to a second round of oral proceedings, the opponent had filed, within the period fixed under R. 116 EPC, a statutory declaration made by one of the previously heard witnesses and proposed that that witness be heard again. The opposition division had decided not to re-examine the witness and not to admit his statutory declaration. For the board, however, the declaration, which dealt with matters that had become relevant only once the new auxiliary request had been filed, was a direct reaction, submitted within the available time, of the opponent (appellant) to that request, and therefore could not be treated as filed late. In deciding not to admit it despite having admitted the auxiliary request, the opposition division had denied the opponent its right to be heard and so committed a procedural violation. The board did not share the appellant-proprietor's misgivings that the declaration conflicted with the case made so far. That submissions filed as a legitimate reaction to an amendment to the counter-party's case contained contradictions was in any event not a proper basis for refusing to admit those submissions from the outset. The board nevertheless observed that several statements made in the declaration were worded in precisely the same way as the new auxiliary request. Given that the points the witness had made were relevant for assessing patentability but supported only by his declaration, the question of his credibility was crucial. That question could be settled only by hearing him again, if necessary under oath before a national court (R. 119 and 120(2) EPC). The board therefore remitted the case to the opposition division for further prosecution with an order that it continue taking evidence by hearing the witness concerned.

In T 1525/17 the opposition division had taken the view that the subject-matter of claim 1 as granted was inventive over E1 and E2 in combination with E3, E4, E5 or E6 but decided not to admit the late-filed citations E5 and E6 because considering them would make no difference to its decision. The board observed that a decision to disregard certain late-filed facts or evidence amounted to their non-admission: "not admitting" and "disregarding" facts and evidence not submitted in due time meant the same thing. The board observed that it was inherently contradictory to take late-filed documents as a basis for an in-depth examination of the patentability requirements, and so consider them as to their substance, yet at the same time declare them not admitted, as the opposition division had done in this case, having fully considered documents E5 and E6 in its thorough substantive assessment of inventive step. As a rule, that documents had been examined as to their substance meant that a board could fully review their examination on appeal or at least that it was barred from holding them inadmissible under Art. 12(4) RPBA 2007 on the basis that they had not been admitted by the department of first instance, when their purported non-admission had in fact been inherently contradictory and so amounted to an improper exercise of discretion (see 
T 2324/14 and T 2026/15).

In T 2053/13 the appellant's (opponent's) inventive step assessment starting from the teaching of document D3 was first presented on the day of the oral proceedings before the opposition division. Document D3 itself had been filed with the notice of opposition; it was however not presented as the closest prior art, but mentioned only in a footnote for a marginal issue. The board recalled that according to G 4/92 (OJ EPO 1994, 149), arguments are reasons based on facts and evidence which have already been put forward. The board considered that rather than merely presenting an additional argument in support of a chain of reasoning already known in an established factual context, the appellant had changed its case. The submission in question introduced a whole new chain of reasoning based on the allegation that document D3 was a promising springboard to the invention as claimed. Thus, the appellant's submission related to a new alleged fact. Filing a piece of evidence did not mean that any alleged fact or objection potentially derivable from that evidence was also introduced into the proceedings. The board was also satisfied that the opposition division had exercised its discretionary power pursuant to Art. 114(2) EPC and R. 116(1) EPC in a reasonable manner when it did not admit the appellant's (then opponent's) new submission.