3.1.6 Re-hearing a witness

In case T 30/12, as evidence adduced for proving the invoked public prior use in opposition proceedings, the appellant (opponent) relied upon the drawing A9 and the testimony of Mr H, made before the opposition division. As regards the request for a renewed hearing of the witness Mr H before the board, the board noted that the appellant did not request that the witness be heard again to supplement his testimony by corroborating facts but only to clarify the statements made before the opposition division. However, the statements made by the witness as to whether document A9 was handed over to a member of the public were clear and unambiguous. The request to rehear Mr H was eventually rejected by the board.

In T 544/14 re-hearing the witness was necessary. In view of the complication and the subsequent delay in the proceedings, the board decided first to clarify whether the alleged public prior use was novelty-destroying (without any doubt, no).

The board in T 1138/20 stated that when the findings of fact of the departments of first instance rely on documents, the boards regularly make an own assessment of the evidence. In case of oral evidence given by a party, a witness or an expert (Art. 117(1)(a) EPC, Art. 117(1)(d) EPC and Art. 117(1)(e) EPC) or an inspection (Art. 117(1)(f) EPC), the boards do not normally assess the evidence de novo by, for example, re-hearing the witness. In such a situation, the board stated the department having heard the witness was better placed to determine the probative value of the evidence given, in particular, the credibility of the witness (i.e. the witness' truthfulness and honesty) and the reliability of the testimony (i.e. its accuracy, e.g. how accurately the witness remembers and recounts the events). The boards could then defer to the first-instance department's evaluation of evidence. (On this point, see also T 423/22 above.)