Well - isn't the big claim to fame of the 1911 design the ability to carry it "cocked & locked". So as long as you don't thumb the safety off, you're perfectly safe regardless of where your trigger finger is.
Besides, as I recall the movie, the hero could draw those things from under a coat and drill about 15 gangsters before they could even get their guns drawn. So I suppose it would be something of an advantage to pull them with finger on triggers.
I expect this rig is really more of a movie prop than practical gun carry attire. But, who know - perhaps it might appeal to some. And no doubt about it - the coolest looking rig for carrying a pair of 45's.