Looks pretty convincing, but of course it could simply be a friend or a prankster in a gorilla costume. Graded B.
The profile of the figure is more suggestive of a human rather than old man Squatch: http://tinyurl.com/3v7372p
If I were directing a scene, that I was also in, I would make directorial movements that would not be noticed. With that in mind, notice that the kid swipes at a (supposed) insect with his left hand and, at that same moment, the figure appears from behind a tree moving in the direction of the hand swipe. Also, the camera angle seems to anticipate the action beyond the hikers. Probably not academy award winning stuff but Bigfoot... ? No.