In principle, the case-law of the Court of Justice has stated that a legitimate expectation that aid is lawful cannot be invoked unless that aid has been granted in compliance with the procedure laid down in Article 1(3) in Part I of Protocol 3 [46], remarking that a diligent business man should normally be able to determine whether that procedure has been followed [47].Notwithstanding this, the Court has also accepted that in exceptional circumstances a recipient of aid which is granted unlawfully because it was not notified may rely on legitimate expectations that the aid was lawful in order to oppose its repayment [48].
Tästä huolimatta tuomioistuin on kuitenkin myöntänyt, että sääntöjenvastaisesti myönnetyn tuen saaja voi, silloin kun sääntöjenvastaisuus johtuu ilmoittamatta jättämisestä, vastustaa tuen takaisinmaksua ja vedota poikkeuksellisiin olosuhteisiin, joiden perusteella se on voinut perustellusti luottaa tuen sääntöjenmukaisuuteen [48].