Deliberate mistake: April wears a watch and bracelet on her left wrist, but after Fin is swallowed by the shark, when April puts her hands on her head in the closeup it's a flipped shot - note the watch and bracelet are on her right wrist.
Deliberate mistake: After the AN-12 launches from the carrier, you see U.S. Navy near the nose of the craft, and MG on the tail code (MG=McGuire Air Force Base). Also, during the flight shots, the plane transforms between a C-130 and AN-12 multiple times.