regarding the question about jumping off a lift going in reverse: assuming the alignment is ok and the rope isn't going to derope to the inside while running backwards (don't think about this too much, you'll never ski again) the decision on jumping may depend on your location. knowing that the uphill load of people will eventually decrease and the lift will slow and stop it may be better to ride it out if you are on the upper half of the line. you'll be going around the wheel if on the lower half of the line (roughly, depending on friction). you might get tossed out (depends on line speed) or you may just go around the wheel and back up.
from the initial twitter feed: "chairs were swinging wildly and throwing people off going backwards through the loading area".
Ever load a chair and it stops right after you get on? Your tails hook up and get caught, now do that going really fast ....