Ah, 2:14 is the top of the pine... yeah, that's the knives hitting the butt as I'm working the feed bar to fold some limbs. At 1:45 it blew some vapor dragging the knives trying to get something in. If I think of it, I'll chip another similar tree, then shut it down and check the temperature of the knives.
Watching (and listing to) the video, I know it's not reversing in the video. I know the controller has a reverse function but one of the things the 720 is a manual control valve unlike the rest of the lineup with an electric valve and reversing autofeed. I'll have to check.
ETA, before I hit send. I checked the schematic and the 720 doesn't appear to have the plumbing to have reversing autofeed. I stand corrected!