Even if he'd practiced the exact shot many times and knew exactly how to aim, he still had to pull it off, and that's very, very fine shooting (3 out of 6? OMG!). A bowling pin's about 5 inches across, so that's something like a 4 to 5 MOA group, offhand, with iron sights. I'll bet you won't find too many shooters who can do that with a rifle, let alone a semi-auto handgun.
Just to put it in another perspective, I shoot in a couple of Bullseye leagues. The standard NRA slow-fire target (B2) has a black (the 8-10 scoring rings) that's about 3 inches across. At the standard 50' distance, that computes to about 18 MOA. Shooters who can keep all their shots in the black are considered pretty damn good, and they're shooting indoors. That guy is keeping most of his shots in the equivalent of the 10-ring, with all the added variables that shooting outdoors adds. He's one in a million, I'd say.