I really liked the finale too. Great challenges and Chris was definitely my pick to win once Gabby and Chee were eliminated. I wanted Chee to win because every time he didn't get to shoot, he was visibly disappointed in the lost opportunity, even if it was an elimination challenge.
As for the dueling trees, I think they were having issues too, but I don't think they stopped the competitions because of them. In the shot where one of the targets got stuck, I think it swung around to an exposed position from the recoil of the next target being hit. Kind of sloppy, but hard to tell if things would've been any different had they worked flawlessly.