2.3. Causal link between the violation of the right to be heard and the final decision
2.3.2 First-instance proceedings
When reviewing first-instance proceedings the boards' review is, in principle, not limited to fundamental violations of the right to be heard.
However, remitting a case to the department of first instance under Art. 11 RPBA also requires a "fundamental" deficiency in first-instance proceedings, and under R. 103(1)(a) EPC the appeal fee is only reimbursed in case of a "substantial" procedural violation. In T 689/05 the board linked these concepts, stating that a "fundamental" deficiency within the meaning of Art. 11 RPBA is not caused by all procedural violations but rather only by a "substantial" procedural violation. See also chapters V.A.9.4. "Remittal following fundamental deficiencies", V.A.11.6. "Substantial procedural violation" and V.A.11.7.1 "Causal link between substantial procedural violation and filing of appeal".
In T 1550/18 the board concluded that in view of a causal link between the infringement of the right to be heard and the decision handed down by the examining division, the infringement constituted a substantial procedural violation justifying the reimbursement of the appeal fee under R. 103(1)(a) EPC and a fundamental deficiency requiring an immediate remittal of the case to the department of first instance under Art. 11 RPBA (see also T 1655/21 and T 1677/21). In J 7/83 a substantial procedural violation was defined as an objective deficiency affecting the entire proceedings (see also T 1529/20 and T 135/22), in J 11/20 as affecting the reasons on which the appealed decision was taken (see also T 135/22) and in T 682/91 as a deficiency adversely affecting the rights of the parties (see chapter V.A.11.6.2 "Violation must be substantial and affect the entire proceedings").
In T 2024/21 the examining division did not appoint oral proceedings requested repeatedly by the applicant in particular for the discussion of the objections under Art. 84 and 123(2) EPC. According to the board, the examining division's approach of informing the applicant at that stage of the proceedings that it had not admitted the amended documents of the patent application under R. 137(3) EPC and that there had therefore been no valid text to which the applicant had given its consent under Art. 113(2) EPC constituted a substantial procedural violation. Moreover, it was evident from the further course of the proceedings that this procedural deficiency had adversely affected the entire further proceedings.
In T 990/91 the lack of opportunity to reply to a supererogatory and incidental argument put forward by the examining division could not be considered to be a violation of the right to be heard, let alone a substantial one.