The right to be heard is a fundamental right of the parties which has to be safeguarded irrespective of the merits of a submission. The necessity to respect it is absolute and cannot be made dependent on a prior assessment of the likelihood that the petitioner's arguments would have convinced the board (R 3/10, R 5/13). In the context of review proceedings the Enlarged Board is not entitled to go into the merits of a party's case. It is not entitled to assess whether or not and to what degree, if any, a party's standpoint which it alleges it would have taken had it been given the opportunity to present it, would have been well-founded (R 3/10).

In R 21/11 the Enlarged Board stated that it could not be ruled out that a different decision would have been reached if the party had been heard on the point on which it alleged its right to be heard had been infringed.