Revealing mistake: There's one bit where we see the shark slamming into a boat and gliding along the side with its mouth open. Not only does the shark's latex mouth bend beneath the snout, narrowing from pressure, but within the mouth you can clearly see yellow hydraulic tanks to open the mouth. (01:22:05)
Visible crew/equipment: When Brody drives across the deck and then onto the ferry, as he does you can see the large shadow of crewmembers and a camera set up, standing on a high ledge above, cast on Brody's Amity Police van. (00:03:20)
Visible crew/equipment: When the shark capsizes Doug's boat, you can, for a few seconds, see the mooring rope that is used by the crew to tip his boat over. (01:23:38)
Answer: Teach me tonight is the name of song when Chief Brody and his wife Ellen are dancing to.