IIRC the HK employee's fees were in the $60k range when all said and done and that was a good shoot.
According to the shooter it was $90K (which IME is about right) and HK paid half.
If a riccochet hits a bystander,
Research the doctrine of transferred intent.
or you pull a gun on the wrong person
Depends on state law and whether reasonable mistake is allowed for or not. This varies by JX.
Your overall point is what I was getting at before though. The sentencing enhancement of using a NFA item if convicted is very sever.
There is simply not enough evidence to say that use of an NFA item will in any given case cause there to be a greater likelihood of prosecution.