Think about your physics, dude. If the sway of that tree was enough to cause it to snap, don't you think the sudden impact is going to cause an even larger snap to occur and in the opposite direction of the impact? Which means directly backwards and then down in your face. Classic definition of whiplash.
If you don't think the sudden jerk on your tractor isn't harming your clutch and drivetrain, you're smokin' some real good stuff.
Tell you what, get yourself a small car and get it stuck really good in some mud. Hook your chain to the front bumper and pull it out with your method. Wanna place any bets on what that bumper looks like when you're done? The same thing is happening to your tractor, just in small increments.
Momentum is a wonderful thing and it certainly can allow the tractor to do more than it may with just the shear pulling force it can generate. Nobody is arguing that point. But the price you are paying is your safety margin.
Good luck to ya; you're gonna need it. Maybe not today, maybe not tomorrow, but your odds are getting better and better.
The fact that you are still alive is nothing short of amazing.