The Prisons here used to use British Enfield .38 revolvers that would quick shoot when you put them back in the holster, many a flesh wound incurred from them before they introduced S&W .38's double action.
Most accidents occurred on the range with wannabe John Wayne's.
And people often type TEH instead of THE because of the natural finger progression, all part of the brain processing movement and trying to take over to make our life a bit easier.
Thick fingers don't help either!
Psychology is an application in robotics.
If we are talking about Quick draw holsters for single action revolvers, I think Arvo Ojala had a lot to do with their emergence.
At least that is what I have always read in gun magazines.