Its hard to figure the angle. I think the hummer was on a pretty good sidehill and the cruiser was at the bottom of it. That would explain the acceleration as well as the way the Hummer keeled over. It also explains why they didn't pull more straight on.
Its fun to mock the other brands but if you are not getting or giving a tug when you're wheeling with a group then you're not having as much fun as you could be.There's no shame in being pulled out.