When the plane loses power and starts to go down, the men seated on the port side of the cabin are shown clinging to their seats against the angle of descent, the tail end on the left higher than the nose on the right. (This is also consistent with the shot of the cockpit from the starboard side, showing the angle of the plane high on the left, toward the tail, sloping down to the nose to the right.) The shot of the men on the starboard side of the cabin should show the same angle of descent in reverse: the plunging nose on the left, the higher tail on the right. But instead, the shot of the starboard side shows the same tilt as the port side - higher tail on the left, lower nose on the right - which, taken literally, would mean the starboard side of the plane was plummeting to the ground in the opposite direction of the port side.
The rocket launched is depicted by stock footage of a V2 launch. However, a scene from overhead shows a different rocket being launched, evidently from Rocketship XM1.
When the party runs towards the sea, the ground is shown splitting apart. A fallen tree lies across the gap. But when the first members of the party approach the split, the tree is shown falling across the split.
When Briggs slips from Rostov's grasp, an overhead shot shows him falling backward into a cloud, as Rostov lays stretched over the ledge above. But the moment Briggs disappears into the cloud, Rostov suddenly dissolves and you see only an empty ledge. (The next shot, a close-up of Rostov, shows him still laying flat on the ledge.)
When the rocket is reported to be flying over water, a picture of a naval vessel is shown. The vessel is the battleship USS Maryland, in a picture taken before Pearl Harbour configuration. She was refitted after Pearl Harbour, and decommissioned in 1947, four years before the movie was made.
The Triceratops and Brontosaurus are portrayed as vicious killers that attack without provocation. In reality both were plant eaters that probably attacked others only in self-defense.
At approximately 32 minutes into the film, Hugh Beaumont can be seen and heard laughing in the background as one of the men is pulled up onto a ledge on the mountainside. For a moment, the actor being pulled is upside down in a humorously compromising position, which is apparently what caused Beaumont to 'lose it'.
Despite many days of trekking all of the men are clean-shaven.
No water supply is evident.
When Major Nolan gets up to go into the back of the aircraft, prior to refueling, he bumps the throttle control housing which moves. This housing is affixed solidly to the aircraft in reality.