64Likewise, when the Commission relies on evidence which is in principle sufficient to demonstrate the existence of the infringement, it is not sufficient for the undertaking concerned to raise the possibility that a circumstance arose which might affect the probative value of that evidence in order for the Commission to bear the burden of proving that that circumstance was not capable of affecting its probative value. On the contrary, except in cases where such proof could not be provided by the undertaking concerned because of the conduct of the Commission itself, it is for the undertaking concerned to prove to the requisite legal standard, first, the existence of the circumstance relied on by it and, second, that that circumstance calls into question the probative value of the evidence relied on by the Commission (Case T-141/08E.ON Energie v Commission [2010] ECR II-5761, paragraph 56).