Art 113(1) EPC: It is the opponent’s responsibility to present all facts relevant to an alleged prior use and to offer suitable evidence (pursuant to Art 117(1) EPC inter alia documents, objects of inspection and witnesses). If witnesses are only to confirm the facts previously submitted, the relevant facts are not brought into the proceedings for the first time by the witnesses, but are merely confirmed by them, whereby (provided the credibility of the witnesses and the credibility of their testimony) the facts can be considered established. It is not permissible for the Opposition Division, in the context of an anticipated assessment of evidence, to make speculations as to what a witness will be able to remember and what he will not be able to remember. The principle of free evaluation of evidence is only applicable after the evidence has been taken and cannot be used to justify not taking evidence offered (see T 474/04, reasons point 8 with reference to G 3/97, reasons point 5). If a complete statement of facts has been submitted, the evidence offered must therefore be taken and can only then be assessed. The anticipated assessment of evidence by the Opposition Division constitutes a substantial procedural violation which justifies the reimbursement of appeal fees (EPO BoA 11 April 2018, T 2238/15).