When Walters was making his SOS radio call, the engine sound should have been heard. However, with no oil pressure the engine would have seized up; thus, no engine sound.
The remote hunting cabin is wallpapered with newspapers, but a close look shows the newspaper used is The Hollywood CITIZEN-NEWS, an unlikely publication to have handy in the high Sierras.
When Howard Walters radios his mayday distress call, he gives his number as 14536. When he jumps from the plane, the number on the underside of the wing reads 23621. When the plane crashes and flips, just before the explosion, the number on the top of the wing is NC414N.
In the (very unconvincing) effects scene of the plane crash, the model used is a different type of aircraft from the one "Howard Walters" is shown as parachuting from in the flight scenes.
The fake background behind the Walters' as they drive to the airfield is obvious. Mrs. Walters does not steer around any of the curves; the transmission is in park; and the Walters' car passes through another car as if it is a ghost.
The scenery outside the airplane keeps changing as well as the altitude of the airplane.
Lt. Tragg testifies that Howard Walters spent the winter at the cabin of Zack Davis. How could Tragg know? The only people who knew were Davis, whom Tragg admits he cannot find; Walters, who is deceased; and Janice Atkins, who was not then volunteering any information.
Janice Atkins seems genuinely surprised to learn that the missing Andrew Taylor was murdered by Howard Walters. It should have been obvious to her from the start that killing Taylor was necessary to frame him and keep him from denying involvement in the theft of $130,000 from his father's company.