> ECC could also help to raise the alarm when you're under attack – the chances of flipping enough bits to evade ECC (and have them be the right bits to pull off your exploit) without getting a few detectable flips in the process must be quite slim.

I'd strongly suggest reading the linked paper. The upshot is: no, the chances are actually quite good that ECC won't save you by raising the alarm, because of the poor job most vendors do of surfacing ECC errors.