>If you treat the software as a black box and only study run time behavior, you have no idea if you have tripped a countermeasure that silences the malicious behavior; if you study the control flow directly, you can look for such countermeasures.

It would be great to find such a countermeasure, and be able to trigger it reliably, or assert the behavior on a permanent basis. Considering that particular weakness of such countermeasures though, wouldn't the safest [for the attacker] default countermeasure likely be to simply crash the device?