Precisely because they are FALSE alarms Pittsy. What validates it? I don't know but its probably based on previous MARMS detection information in both actual failure cases.
Add in the requirement for additional MOD 45 polling at 5 minute intervals, the requirement to have two consecutive alert polls, MARMS downloads after every flight and the NDI and you can get some idea where EC is coming from with this.
The problem is not that the MOD 45 warning is not detecting, the problem is that it thinks its detecting when its not really detecting anything bad.