Plot hole: When Jack The Ripper checks his watch before confronting H.G. Wells and demanding the key, the hands point to 8:50, the ensuing chase to the museum and demise of the Ripper may have used up a half hour or so, yet the time on the wall clock indicates that it is midnight.
Plot hole: In one scene saboteurs rig the Concorde's cargo door to automatically open suddenly in flight, on the principle that the rapid decompression will cripple the airplane & cause it to crash. At the critical time the door does start to open, but jams and only opens very slightly. Minutes go by, with the ajar hatch allowing air to freely pass through. Then, suddenly, the door unjams, and the compartment is shown losing air pressure dangerously fast. Problem is, that since the door had been cracked open for several minutes, the air pressure would surely have gotten to equilibrium by that time. (01:32:45 - 01:36:30)
Plot hole: How did Professor Krassman get shocked into being a frog? The electronic device doesn't even touch his head.