Continuity mistake: When Sam and the other girl fall down the mountain, at one shot Sam unlocks the girls snowboard and it drops down the mountain but at one shot before the ski patrol throws the rope down to them you can see (for a second) on the right side of the girl, the corner of the snow board. Then she doesn't have it.
Continuity mistake: When Sam comes over to say goodbye, its snowing outside. And Johnny gets a collection of flakes in his hair. But when he goes inside the flakes in his hair are completely gone.