I would argue the following basis , and ignore completely the case they quote (which has been addressed in other answers):
The airline has claimed that it undertook an inspection, but that the fact nothing was in fact found to be wrong, causes this to be exceptional and outside their control.
However, a responsible proactive safety conscious airline, will always err on the side of caution. Therefore if in doubt they will check in depth, even if nothing is eventually found, because this is good safety practice.
As a result, a proportion of suspected issues will always turn out not to actually show a fault, AND, this reflects normal consequences of a diligent proactive and risk avoidant approach to safety. Being an expected event (however uncommon) that results from proper safety practices, it does not represent, and cannot be, either exceptional, or outside the control of the airline, in the sense that is required by governing law.
tl;dr - please don't fabricate fallacious reasons not to follow the law, and pay my costs in full.