Continuity mistake: When Bond is flying over China and landing on the sea by Scaramanga's island, you can see that his plane has two floats - one on either wing. But in the shot where he is heading for the beach, it is clearly seen that the left float has gone! (01:28:40 - 01:30:55)
Visible crew/equipment: At the very end, when Thunderbolt snaps the celebratory cigar in half, in the next shot as the Cadillac pulls away, the reflection of crew is visible on the rear of the car.