This is partially correct -
But I'm wondering if he never actually lowered the hammer with the decocker while at the range, because it is pretty obvious what it does when used on a fully cocked pistol.
eta: Ah, there it is -
1. I'm sure you would have been quite entertained this am with my Ruger P89 to see me trying to figure out what the decocker was doing when I engaged it in D/A mode.