3.1.2 Offering evidence – effect on the outcome of the dispute

See the introduction above with reference to T 329/02 and T 860/01.

According to T 716/06, it is true that where oral evidence of a witness is requested by a party the competent EPO department should grant this request only if it considers this oral evidence necessary, i.e. when it is required to clarify matters that are decisive for the decision to be taken. If a request is made by an opponent to hear a witness on an alleged public prior use and on the disclosure of a certain feature by this prior use, the competent department of the EPO must as a rule grant this request before deciding that the alleged public prior use is neither established nor a novelty-destroying part of the state of the art because the feature in question is not found to be disclosed therein. In T 2003/08 of 31 October 2012 date: 2012-10-31 the board – in contrast to the opposition division – considered it appropriate to hear the witnesses because their testimony could affect the outcome of the proceedings.

In T 246/17 the opposition division had declined to hear the witnesses offered in relation to prior use and considered the public prior use to be adequately proven by the documentary evidence. However, the board came to the conclusion that it could not be ruled out that hearing the witnesses, alongside evaluating the documentary evidence, could have led to a different assessment of novelty and inventive step and thus to a different outcome. The disclosures of documents O1 (manual) and O2 (brochure) left open whether certain features were present in the instrument described, but the instrument had actually been made and sold and might itself have disclosed them even though O1 and O2 did not, and this was a matter which witness testimony could resolve. Not hearing the witnesses was therefore a fundamental procedural violation that justified setting the decision aside (see e.g. T 716/06, T 1363/14 and T 314/18).

In T 1100/07 (alleged prior use, sale of a vehicle with a given feature), the department of first instance had refused to hear two witnesses. The board held that it had been right to refuse to hear one of them, as he would merely have confirmed what he had said in his written statement about documents that anyway spoke for themselves and hearing him would have had no impact on the final decision. It should, however, have heard the other witness. It was true that the request that he be heard had been filed late and that granting it would have meant adjourning the oral proceedings, but the opposition division had based its final decision on a failure to establish the prior existence of a single given feature and the witness would allegedly have been able to give evidence on that very point. Thus, the refusal to hear him was wrong and might have affected the outcome of the decision.

In T 273/16, during the opposition proceedings the appellant-opponent had, on multiple occasions, requested that two witnesses be heard on the alleged prior use of a commercial dishwasher. The opposition division had opted not to invite the witnesses. Its decision appeared to be based primarily on the fact that no production or sale of the dishwasher had been demonstrated. Yet the opponent had offered the two witnesses in relation to that very issue. The decision not to hear the witnesses was therefore incorrect and might have influenced the outcome of the proceedings.