In T 1411/08 and T 1515/07 the boards considered that the examining division had to be held to have committed a substantial procedural violation because it had not performed an additional search that was manifestly necessary (see also T 1924/07). In T 1924/07 the board held that a distinction had to be drawn between, on the one hand, whether the examining division had acted despite realising that the features were technical and not notorious, thereby indicating a situation where a search was "manifestly necessary" (cf. T 1515/07 and T 1411/08), and on the other hand, whether the features had been erroneously overlooked or misjudged, i.e. an "error of judgment" had occurred (cf. T 690/06 and T 698/11); the latter case could not be considered a procedural violation (see in this chapter V.A.9.5.10).

In T 736/14 the board held that, if an applicant whose application is non-unitary responds unclearly and/or in a misleading way to an invitation from the examining division to designate which searched invention it wishes to prosecute further, it could not be automatically assumed that the applicant selected the invention covered by the main request for examination. Rather, the examining division had to clarify, e.g. via a further communication, which of the searched inventions the applicant actually wanted it to examine. Confronting the applicant with an irrevocable decision not to admit an auxiliary request covering one of the inventions searched, without giving an opportunity to comment on its admissibility beforehand, constituted a substantial procedural violation of the applicant's right to be heard. In T 291/93 it was held that a simple reference by the appellant to an inadequate search of the prior art could not be taken as sufficiently supporting an allegation that a substantial procedural violation had occurred.