Continuity mistake: When Thorndyke and Havershaw are working in the garage towards the end of the movie, you can see Thorndyke brings down his oil pistol from the ramp when Havershaw reminds him about the wager he made with Mr Wu, but in the next shot Thorndyke is holding his oil pistol near the ramp again.
Havershaw: Here it comes again, sir.
Thorndyke: Havershaw, I'm not a cowardly man. But, I am beginning to sense, and that thing is out to get me.
Havershaw: Now, now. None of that, sir. We're not losing our nerve, are we?
Thorndyke: Blast you, Havershaw! How dare you patronize me! I am not losing my nerve.
Havershaw: No, sir. No, sir, of course not. No, no.