If the way in which a department of first instance has exercised its discretion on a procedural matter is challenged in an appeal, it is not the function of a board of appeal to review all the facts and circumstances of the case as if it were in the place of the department of first instance, and to decide whether or not it would have exercised such discretion in the same way as the department of first instance. A board of appeal should only overrule the way in which a department of first instance has exercised its discretion if the board concludes it has done so according to the wrong principles, or without taking into account the right principles, or in an unreasonable way (T 640/91, OJ 1994, 918; see also T 182/88, OJ 1990, 287; T 986/93, OJ 1996, 215; T 237/96 and G 7/93, OJ 1994, 775, T 1119/05 and T 1707/07.
A board of appeal, when reviewing the opposition division's exercise of discretion under Art. 114(2) EPC, has the power to overrule a decision not to admit a late-filed ground of opposition, if the board concludes that the opposition division based its decision on manifestly incorrect technical assumptions or on an erroneous approach to applying said ground of opposition since this amounts to a misuse of the discretionary power under Art. 114(2) EPC (T 109/08).
In T 1849/12 the impugned communication of the examining division under R. 71(3) EPC which was qualified as a decision had not terminated the proceedings as regards the appellant. Thus, it had adversely affected the appellant by issuing its communication in a way that could not be remedied by means of an appeal after the final decision. The examining division therefore ought to have allowed a separate appeal, especially since the EPC made no provision for an appeal against inaction of the EPO (see, to that effect, also J 26/87, OJ 1989, 329). The examining division had failed in its deliberations to take proper account of a crucial factor and so exercised its discretion improperly. Its communication therefore had to be regarded as a separately appealable decision.