In T 432/12 the decisive issue was whether there was a sound and plausible reason in this specific case for filing the documents only in the appeal proceedings. In principle, documents could be admitted in the case of e.g. a normal reaction to a late turn of events in the opposition (oral) proceedings, an exceptional interpretation by the opposition division at a late stage or in the decision, or evident non-allowability in view of the newly cited documents and/or objections, (see also T 169/12). However, none of these exceptions applied to the case at hand.
In T 724/08 the appellant had already raised a novelty objection in its opposition and therefore could have submitted the late-filed documents during the first-instance proceedings. It was immaterial whether the appellant had indeed only come across these Japanese patent specifications or the corresponding Patent Abstracts of Japan by chance later or whether said documents had genuinely been difficult to find, because it was not permissible to use these issues to slow down proceedings or gain an unfair advantage over the other party. In exercising this power, the board could make admitting a citation into appeal proceedings dependent on whether it is prima facie relevant but the board was not obliged to do so, because otherwise an opponent could easily submit a (highly) relevant citation for the first time in the statement setting out the grounds of appeal and expect the citation to be admitted into the appeal proceedings on grounds of relevance.
In T 1314/12 the board added that this would mean that a proprietor could be obliged to repeatedly defend its patent against new attacks throughout the entire opposition and opposition appeal procedure. However, this was clearly incompatible with the requirement under the EPC and the RPBA that all relevant information be presented within certain time limits.
In T 2471/13 the prior art document filed with the statement of grounds and objections based thereon could and should have been filed in first-instance proceedings. The board decided not to admit the document into the proceedings, irrespective of its potential relevance.
In T 910/11 the appellant (opponent) raised a new line of attack under Art. 123(2) EPC against claim 4, which had been held to be allowable by the department of first instance. An objection could therefore clearly have been raised at first instance. Nor was any explanation offered as to why this objection had not been raised earlier. In view of the absence of justification for the late filing of this new attack the board decided not to admit it into the proceedings (see also T 169/12).
In T 2193/14 the board considered the admissibility of documents filed with the statement of grounds of appeal for the purpose of questioning the validity of the subject-matter of granted dependent claims against which no substantiated attack had been made in the notice of opposition. The board decided not to admit the documents into the appeal proceedings. These documents should and could already have been submitted before the opposition division.
In T 2187/14 a second machine translation that was filed to replace an inital incomprehensible machine translation was not admitted.
In T 876/05 the board rejected the opponent's argument that filing new documents a few days before the oral proceedings before the department of first instance was destined for failure and that it was therefore preferable for him not to file those documents until the appeal stage. The board held that Art. 10a(4) RPBA 2003 (Art. 12(4) RPBA 2007) put documents that could have been submitted before the department of first instance and documents which had been submitted but had not been admitted on an equal footing. Had these documents been filed in the opposition proceedings, the worst that could have happened was that they would have been regarded as inadmissible by the opposition division, so the consequences would have been no different than if they had not been filed. The board decided, when examining the patentability of the filed requests, to consider only the documents that appeared immediately relevant (T 624/04).
In T 1715/08 the board held all the evidence submitted on appeal to be late-filed and did not admit it. All of it could have been filed during the opposition proceedings. The arguments based on it (new objection of lack of inventive step) were disregarded.
In J 5/11 the Legal Board stated that the Office's duty to examine evidence of its own motion is more stringent in relation to evidence that is in the public domain, and the case for admitting such evidence when it is filed out of time by the parties is correspondingly stronger. The Office's duty to examine of its own motion evidence that is in the private sphere of the party concerned is obviously limited. Such evidence can only be taken into consideration by the Office if it is brought to the Office's notice by the party concerned. If evidence of that type is not put forward in the proceedings before the first-instance department of the Office, it is difficult to see any compelling reason why the Board of Appeal should exercise its discretionary power under Art. 114(2) EPC and Art. 12(4) RPBA 2007 in such a way as to admit the evidence when it is filed with the grounds of appeal or a fortiori at a later stage of the appeal proceedings. That is particularly true when, as in the present case, the first-instance department has expressly drawn the appellant's attention to the need for supporting evidence, indicated precisely what type of evidence is needed and given the appellant an adequate time limit within which to file the evidence.