I think he means landing "in front of the tree" where the tree is behind you. If you can't take a stance, you may mark behind the tree (using the solid object relief rule) and then have to deal with the tree.
i am confussed...do you mean your disc lands with a tree in front of it or a tree right behind your disc. either way if you learn how to throw a disc side arm it can help it these matters. also you don't have to kill the shot, check out your options and throw to a spot where you can make a good shot to get out of the hole with minimal danage to your srocecard.