270 WSM, 300 yards, no mention of the bullet type.
Doesn't matter though, why anyone is arguing that the bullet type is wrong is beyond me. 2 wolves dead, one in its tracks, the other "a few dozen yards away". You can't argue that the bullets didn't work, and as far as I'm concerned you can't be more dead.
The first wolf was hit high due to the down hill shot trajectory (guessing, I like everyone commenting here, wasn't there) any animal hit high through the chest cavity rarely leaves much of a blood trail for the first bit.
Saying it would have been a lost wolf if it hadn't been a frozen river is crazy, any animal can be tracked in the snow, bleeding or not. "A few dozen yards" would not result in a lost animal in any terrain, unless you are the laziest hunter/tracker ever.
Unless you were standing there with the guy, I don't know why so many must pick apart his story and hunt. Guy spent 4 years attempting to take a Wolf, opportunity presented itself, a double at that, the guy did a great job of filming in my opinion and shared his story.
Want to do it different yourself, go for it.
Last time I checked the people here on this site were all on the same side, instead we are acting against each other, and might as well be like the commenters under the story/video link.