Factual error: Doug and Tony time travel to one million years B.C., where they encounter dinosaurs. Not likely. All the dinosaurs were rendered extinct several million years earlier by an asteroid strike. There weren't any left by 1-million BC. (00:29:45)
Continuity mistake: After falling into the quicksand, Nimon's head and right hand are exposed, but the next shot when Tony and Doug arrive to help, only his head is seen.
Continuity mistake: During Tony and Doug's meeting with Nimon and the Magister, the assistant points his laser gun close to Doug's back, but when the Magister signals to shoot, the assistant is now several paces behind Doug, and there was no time for the assistant to step back.
Continuity mistake: Vokar's assistant brings Tony and Doug into the control room, stopping in front of a dome. The assistant is directly in line with Doug and next to the dome, but the next shot shows the assistant standing further from the dome and towards Doug's left.
Continuity mistake: When Vokar's assistant summons Tony and Doug, they are in a room with very dark walls, but the profile shot of the assistant shows a beige wall behind him.
Factual error: Raul Nimon uses a silencer-equipped revolver during his attack in the tunnel control room. In reality, a silencer on a revolver is useless, as the exploding gases from the bullet discharge (the gun blast) would exit from the space between the cylinder and gun barrel.
Revealing mistake: The lizard crawling through the jungle in 1,000,000 B.C. brushes against and nudges a heavy tree.
Revealing mistake: The heavy boulder Tony uses to brace himself to save Nimon easily wobbles as he moves.