There are obviously parameters in logic. An N2 failure would have a result on N1/EPR and EGT. I believe a thrust increase would be momentary at best "Full Authority Digital Control". The logic should be is N1/EPR and EGT within tolerance as N2 could be a loss of indication, follow procedure.
An N2 seizure would most likely be felt and certainly seen as a catastrophic indication. The FADEC response is irrelevant...