I think this would fit much better in the competition forum. Neat trick, not something to use in a defensive scenario.
cool, can it be done with other pistols?
What you saw was a factory spring. The guy in the first Vid is USPSA Grand Master and can do that on demand. He was a full 1.5 seconds faster than two other GMs who shot the same stage and did not use that technique. At that level, 1.5 secs is a huge advantage on this stage.
And yes, he (and others) can do it with other pistols. But this guy, Rob Romero is his name, seems to have developed the most proficiency.
I still say it is one helluva tool to have in the toolbox.