According to T 954/98 of 9.12.1999, the rules for exclusion from a board for partiality should be interpreted not only in the light of the principle of judicial impartiality, but also the principle of "gesetzlicher Richter" (i.e. according to the principle of "the duly designated judge"), such that, firstly, a member whose impartiality was suspect should not handle a case, but secondly that parties should not be able to change the composition of boards at will for no objective reason. Purely subjective impressions or vague suspicions were not enough to disqualify a member. The member's behaviour or situation had to provide objective justification for a party's fears. The mere fact of taking discretionary procedural steps which might disadvantage a particular party was not enough to justify exclusion, not even if the party concerned interpreted those steps as expressing bias against it.
In T 190/03 (OJ 2006, 502) (see also T 283/03, T 572/03, all published on 18 March 2005), the board held that not admitting amended claims, regardless of whether the board had correctly used its power or discretion to do so, would not give rise to an objectively justified fear of partiality. It also held that at the beginning of an appeal case where a properly constituted board had not performed a procedural step, there were generally no circumstances that gave rise to an objectively justified fear of partiality. Finally, it held that the mere fact that the member concerned had given reasons and explanations of the reasons which went beyond the facts, in response to an invitation under Art. 3(2) RPBA 2003, did not give rise to an objectively justified fear of partiality under the objective test.