I wont carry one in the chamber for this reason. I may end up getting a 357 with a heavier double action trigger and feel a little bit better about it though!
I remember reading after I first saw that that he had been practicing with a Glock in a holster with a thumb release holster, then switched to the 1911 with a Blackhawk Serpa holster with a trigger finger detention release. So his muscle memory had him pressing down with the thumb and trigger finger to overcome holster releases, which after swapping guns acted to thumb off the safety of the 1911 and drag the trigger finger into the guard and BOOM!
Practicins different trigger control systems led to conflicting muscle actions.