In unclear cases there can be no presumption that an applicant has waived his right to be heard under Art. 113(1) EPC. Hence a refusal decision pursuant to Art. 97(2) EPC (former Art. 97(1) EPC 1973) based on such a presumption and taken before expiry of the term originally set for reply to a communication contravenes Art. 113(1) EPC and thus involves a substantial procedural violation (T 685/98).
In T 685/98 (OJ 1999, 346) the board noted that prior to a valid refusal under Art. 97(1) EPC 1973 the applicant must either have exercised his right to comment or have waived this right. It held that a simple procedural request made by the applicant after receipt of the R. 51(2) EPC 1973 communication could not be treated as a waiver of the right to present comments during the remainder of the four-month term set for reply. When the applicant neither replied in substance to the objections raised nor waived his right to present comments, then the refusal of the application was ultra vires and voidable ab initio because under Art. 97(1) EPC 1973 the application was to be refused, if no different sanction was provided for by the Convention. However, Art. 96(3) EPC 1973 provides a different sanction for failure to reply, namely the deemed withdrawal of the application.