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.
Deliberate mistake: When George spies on his hedonistic neighbor down the hill with his telescope, the telescope is always level when it actually should have been pointing downward. Same when his neighbor spied on him - his telescope was always level also when it should have pointing upward.
Revealing mistake: When the boy accidentally hits the old man with the ball, he falls over. Note that you can see the stuntman's full head of hair as he hits the ground. When you return to the close-ups of the old man as he gets up, that extra hair is gone.
Continuity mistake: When Amanda rushes to get onto the bus to the train station, the door being opened is at the front LEFT of the bus (as viewed from the back). On arrival at the station (5 scenes later), the door opens at the front RIGHT of the bus (as viewed from the back), and in the second camera shot, the driver of the bus can be clearly seen sitting where the door Amanda used to board the bus would be, with no door there.
Continuity mistake: When Linda Blair deliberately knocks a plate of desserts into one of her suitor's lap, the tray hits him directly in the crotch and the camera shows this. Then there is a cut to Linda Blair's face and then a cut back to the boys clothing and the scene now shows the desserts all over his suit from the shoulders down.Gregg Jasper
Factual error: When they visit "Ireland", presumably the Irish Air Corps aerodrome in Dublin at the time of WWII, all of the staff in the bar at the aerodrome are American servicemen, in neutral Ireland.