Revealing mistake: In the scene where Bond is trying to escape with his new Mini-Jet, he flies through a big hall. If you look carefully, you can see that the aeroplane which is supposed to be flying with its wings vertical is fastened to some kind of sustainer.
Revealing mistake: When Bond and Gobinda are fighting on top of the train, Gobinda rolls over with his sword, which bends like a rubber prop.
Revealing mistake: When the police cars chase Bond and stop outside the circus, you can clearly see a lot of brake-marks. It's quite obvious that the filmmakers re-shot the scene several times, before they got it right, but didn't bother to remove the marks made in earlier takes.
Revealing mistake: When Gobina first slashes at Bond during the climactic fight on the plane, a subsequent medium shot reveals a stunt double (note the bald spot). He's even wearing completely different clothing - a black stunt suit instead of a blue jacket and white shirt. (02:05:00)
Revealing mistake: When Grischka pins Bond to the cabin door with his knives, he takes out a knife and attempts to kill Bond for killing his twin brother. Bond then opens the cabin door and then kills Grischka by opening the cabin door and throwing a knife into his stomach. If you watch carefully, you can see the cabin door begin to open before Bond pulls the cabin handle down.
Revealing mistake: When Bond exits the carriage at the tunnel, it's an obvious stunt double.
Revealing mistake: When Bond sends an assassin crashing into the tank containing the octopus, you can see the assassin is a dummy.
Revealing mistake: When Bond falls off the train the scenery switches from outdoor filming to an obvious film set.