4.5. Kriterien für die Ermessensausübung

In T 842/24 the board found that there was no legal basis for reversing in appeal a decision by the opposition division to admit new evidence (D29) into the opposition proceedings and thus to retroactively reject in appeal specific facts which had been admitted into the opposition proceedings if that evidence formed the basis of the decision taken on substantive grounds. It noted that this reasoning was not in conflict with T 989/23 where the auxiliary request admitted at the opposition division's discretion did not form the basis for the decision to maintain the patent in amended form.

The board recalled that the jurisprudence of the boards of appeal regarding the review of the opposition division's discretionary power under Art. 114(2) EPC was based on a principle established in T 640/91 and G 7/93. However, it noted that this principle was established in the context of reviewing a decision not to admit (emphasis by the board) a requested amendment after issuance of a R. 51(6) EPC 1973 communication (G 7/93) or not inviting a party to file further observations before issuance of a decision to refuse the application (T 640/91), and that it was also applied when reviewing discretionary decisions not to take a party's means of defence into account, e.g. documents. The board was aware that in a few cases this principle had also been invoked in the context of reviewing the opposition division's discretionary decisions to admit (emphasis by the board) documentary evidence on which the reasons for the decisions were based. This had been mainly limited to cases of errors in exercising discretion or procedural errors (T 1209/05, T 1652/08, T 1852/11, T 2513/11). In other decisions it had been questioned whether submissions admitted and forming the basis for the contested decision (evidence, claim requests) could be at all excluded from the proceedings in appeal even if the opposition division had exceeded the proper limits of its discretion in admitting them. The board nevertheless noted that in none of these decisions were the circumstances of the case such as to justify reversal of the discretionary decision.

Given the procedural asymmetry between situations where evidence was admitted or not admitted, the board had strong reservations as to whether the principle established in T 640/91 and G 7/93 was also appropriate for reviewing the discretion exercised in a decision to admit evidence into the proceedings. It explained that, in the context of non-admittance, the only way to challenge a substantive decision that did not take a (non-admitted) means of defence into account was to contest the non-admittance thereof. A review by a board of the discretion exercised by the opposition division was also imperative, if it was submitted that the exercise of its discretionary power constituted a substantial procedural violation..

On the other hand, a review of a decision by the opposition division to admit evidence or a claims amendment into the proceedings was not a necessary means to safeguard a party's right for a proper defence. The board held that the admittance of new evidence, even if its filing was not justified, did not lead itself (emphasis by the board) to an unequal treatment of the parties and therefore a procedural violation. Rather it was the absence of a proper opportunity for the opposing party to respond to that new piece of evidence and submissions based thereupon, once it had been admitted, which constituted a breach of the right to be heard. Art. 113(1) EPC reflected the principle that for inter partes proceedings each party should have a proper opportunity to reply to the case presented by an opposing party (G 4/95). The board noted that T 776/17 also made such a distinction.

The board added that a decision by the opposition division on substantive issues, based on evidence which has been admitted into the proceedings, could still be challenged in substance, on the ground that this evidence lacks relevance or probative value. It did not find any reason why a decision to admit an auxiliary request or piece of evidence should be reviewed on appeal if a party requested it, in order to determine whether discretion was exercised appropriately. The board should instead just fully review the appealed decision in substance. In view of this the board considered that it could not be derived from G 7/93 that the criteria stated therein for overruling the way in which a department of first instance has exercised its discretion also applied to the case where evidence was admitted and the decision taken on substantive grounds was based thereon. The board thus concluded that under the present circumstances it was not empowered to review the way the opposition division used its discretion to admit D29 into the proceedings.

In T 733/23 the opposition division had concluded that there had been insufficient evidence to prove that the data sheets D2, D4, and D7 to D9 had been made available to the public before the filing date. Rather than concluding that, as a result of the data sheets not being considered state of the art under Art. 54 EPC, the subject-matter of the claims was novel, the opposition division decided not to admit them into the opposition proceedings. The board concluded that not admitting these data sheets, filed in due time, constituted a substantial procedural violation (see details as from point 4 of the Reasons including discussion on D19, an affidavit).

The board, in support of its decision, presented some key considerations on public availability of advertising brochures and data sheets, as well as the standard of proof to be applied. The board stated that when a document was clearly intended to be publicly distributed, as was the case with advertising or commercial brochures, the absence of a specific publication or distribution date, a situation quite common in this type of document, was not in itself sufficient to conclude that the document did not constitute prior art. As with any other type of evidence, the key question was not whether the exact date of publication could be determined, but whether it could be established that the relevant subject-matter was made available to the public before the priority or filing date.

Data sheets often represent an intermediate case between internal documents and advertising brochures. Where no publication date is present, the board held it should first be assessed whether the document was intended for public distribution. If so, additional sources must be examined to establish whether the relevant subject-matter was publicly accessible before the patent’s filing or priority date. Here, the opposition division had failed to provide a reasoned decision on public availability, giving no weight to the dates printed on their front pages.

As to the standard of proof, the present board concurred with the position in T 1138/20 that there is only one standard of proof: the deciding body must be convinced, based on the underlying circumstances.

According to the present board, this did not imply that all cases were to be treated identically, as in practice the degree of proof required to establish credibility (i.e. to persuade the board) might vary depending on the specific circumstances. In other words, it was not the standard of proof that adjusted with the circumstances, but rather the credibility of the arguments made by the different parties. For example, when the evidence was exclusively controlled by one party, any gaps in the relevant information might significantly undermine that party's credibility. Conversely, when the information was equally accessible to both parties but only one party submitted evidence, merely raising doubts might not be sufficient to challenge the credibility.

In the present case, the conclusions of the opposition division suggested that the standard of proof "up-to-the-hilt" was applied to determine the public availability of the data sheets. Even if the board agreed that different standards should be applied, this would not be justified in the case in hand, as the relevant information to prove the public availability of the data sheets was not within the exclusive sphere of the appellant (opponent). In this instance, the relevant information would more likely be within the sphere of the patentee. Therefore, there was no basis for applying the strict standard of "up-to-the-hilt" or for questioning the credibility of the appellant (opponent) solely on the grounds that some information was missing.

The patentee argued that, when in doubt, the patent should be upheld. The board disagreed. Fact-finding boiled down to a binary exercise: either something had been proven, or it had not. In addition, there was no presumption of patent validity in proceedings meant to re-assess the validity of this very patent.