The following morning, around the 37-minute mark: After they've spent the night at Dr. Sangre's mansion, Bill and Mac go out to inspect the wreckage of the plane. It's supposed to be daytime, but in all the shots of them outside, it is still dark out.
When Jeff is going to sleep and the clock strikes midnight, it chimes only six times.
The pilot, trying to communicate with anyone on the air, is seated in the co-pilot's seat and another man, who is obviously not flying the plane, is seated in the pilot's seat.
As the plane crash lands on the island, the wire holding it in the air can be seen.
Dr. Sangre tells Mac that his sleeping quarters adjoin Bill's, but later in the film Bill and Mac are seen sharing a bed, with no explanation.
When Dr. Sangre is showing Bill and Mac their quarters, the boom mic shadow is often visible on the wall with the entry door.
When the servants and Jeff are gathered around the dining room table before midnight, the boom mic shadow can be seen on the table moving from speaking character to speaking character.
Bill pronounces their original destination "ba-HAY-muz" instead of "ba-HA-muz".