Training is often used as a means to mitigate the risks inherent in accident prone mechanisms. And yet, training often fails. You having been in the military, no matter how much training in small arms you received, I am sure you know of negligent discharges, some fatal. At one point in the Iraqi/Afghanistan conflict, deaths/injuries due to negligent discharges exceeded combat injuries/deaths.
That is one reason I am leery of striker fired semi auto weapons, they are too easy to accidentally discharge.
The shooting community has gotten used to riskier and riskier firearm mechanisms through
"normalization of deviance". These URL's discuss the basis of this idea: more or less, groups get used to pushing the safety boundaries in, reducing the margins, and one day, kaboom!
Stopping Normalization of Deviance: A Safety Program
Normalization of Deviations in Performance