My guess is that he is pulling from the top--look how the club shallows-out on the downswing. Then he may switch to a driving (hitting) action once the club reaches the bottom of the pully thru low point, thus a 4 barrel swit. Just a guess. One thing is certain he is a very strong and quick Dude, and compression leakage is not a concern.
After watching the video, I wouldn't peg him as solely hitting. But, anyone would say that there are lots of things to like. From the front view they showed on the broadcast, I'd say again that I LOVE the lack of right wrist cock. Beautiful right forearm flying wedge. The right forearm is in a wonderful position for one starting from standard address. And, at impact, it's fantastic. Does anyone have the front view on video??
He may have components of both, but it appears to me he's driving that right side. Just don't see anything that indicates the class (snead, els) swing. Doesn't appear to be a lot of pulling with him.