4.2.1 Ranking of means of evidence

The board in T 2659/17 observed (with reference to T 474/04) that an affidavit carried less weight than testimony. It found, therefore, that decisions should not be based solely on an affidavit, but rather the person who had made it should be heard as a witness whenever offered by a party. This applied all the more in the case in hand since the patent proprietor had challenged the content of the affidavits and demanded that the offered witnesses be heard. Denying it the opportunity to question those witnesses had prevented it from rebutting the ultimately crucial evidence. This was even more serious given that evidence for the prior use lay largely within the power and knowledge of the opponent (violation of Art. 113(1) EPC). See also T 329/02 in this chapter III.G.3.3.4.

In T 918/11, the board held that a mere reference to the fact that testimonies B1 and B2 concerned facts which had occurred at least 14 years ago and that other documentary evidence might possibly exist did not suffice in the case in hand to dismiss the testimonies as insufficient. It went against the general rules concerning the consideration of evidence to distinguish dogmatically between the evidentiary value of a witness testimony on the one hand and a document on the other hand. The opposition division had apparently considered documents to be of a more conclusive evidentiary value than witnesses. Such an approach had no basis in the EPC, Art. 117 EPC containing no ranking of the means of evidence it listed (see also T 2565/11, in which it was similarly found that witness testimony and documents were not ranked in this way).

See also in this chapter III.G.2.4.1 d) and III.G.2.5.4.