In T 663/99 the board decided that the patent proprietor's right to be heard was violated if the time limit fixed under R. 57(1) EPC 1973 for presenting comments on the opposition had not expired by the date of handing over a revocation decision to the EPO's internal postal service (see also T 804/94).
In T 1081/02 the board of appeal decided that the principle of the right to be heard had been violated, since the opposition division, after inviting the patent proprietor to file within two months the documents considered necessary to maintain the patent, did not wait until this time limit had expired but issued an interlocutory decision prior to its expiry.
In T 685/98 (OJ 1999, 346), the board held that the phrase "fails to reply in due time to any invitation under ... paragraph 2" in Art. 96(3) EPC 1973 had to be construed in the light of the purpose of the invitation pursuant to Art. 96(2) EPC 1973 and R. 51(2) EPC 1973, which was to afford the applicant an opportunity to exercise his right to present comments in accordance with Art. 113(1) EPC 1973. Hence, a letter from the applicant which neither exercised nor waived that right was not a reply for the purposes of Art. 96(3) EPC 1973. In the case in point, the examining division believed erroneously that the applicant, by making a simple procedural request by return of post, had somehow forfeited his right to present comments during the remainder of the four month term set for reply. Thus the precipitate refusal, while there were still some two months of the term for reply unexpired, did contravene Art. 113(1) EPC 1973.