FBI found it was entirely possible to disable the striker block without the trigger being pulled. A combination of wear, inadequate design, and loose manufacturing tolerances.
To disable the striker block, they removed the rear plate, applied pressure to lift the slide up and away from the grip, then stuck a punch into the back of the gun to manually release the sear. Maybe this is the beginning of discovering an issue with the striker block, but this isn't simulating a failure that could happen under normal circumstances (specifically jamming a punch in the back and releasing the sear).
To disable the striker block, they removed the rear plate, applied pressure to lift the slide up and away from the grip, then stuck a punch into the back of the gun to manually release the sear. Maybe this is the beginning of discovering an issue with the striker block, but this isn't simulating a failure that could happen under normal circumstances (specifically jamming a punch in the back and releasing the sear).