Continuity mistake: When Austin is working his mojo on the fembots, take note of his pile of clothes that have been carelessly tossed into the corner of the room. Whenever the shot returns to Austin dancing around, the pile of clothes seem to have changed their arrangement. (01:14:00)
Revealing mistake: When Patty O'Brien (the Irish assassin) fails to strangle Austin in the restroom, Austin grabs him and shoves his head in the toilet. If you look closely, right before O'Brien's head enters the toilet, the back of his hair is already wet. (00:32:30)
Factual error: In the film Austin has a Boeing 747-300 as his personal jet. This model of the 747 was not released until 1980, and he was frozen in 1967.
Continuity mistake: When the security guard comes back with the orange sherbet, he hands it to Austin who takes it from him. But a few seconds later, when Austin and Vanessa are escaping from the destructing lair, neither Austin or Vanessa have the sherbet with them. [Just a note regarding this scene, the international version of the film contains this scene but not the US version. I believe it is a deleted scene on the US version of the DVD.]
Factual error: The British soldiers (quartermaster at the MOD, MPs and paras) are all wearing inaccurate uniforms and insignia.
Continuity mistake: When Austin gets unfrozen and is taking a shower, when he finishes he still has some of the "warm liquid goo" running down the left side of his face (his left). However, when he's about to get dried off, the goo isn't there any more. (00:09:35)
Factual error: When Mrs Kensington pulls up in the Jaguar to save Austin from the hordes of women chasing him at the start of the film, the car does not have a front number plate, which has always been illegal in the UK, even in the swinging 60's.
Continuity mistake: When Austin first encounters the fembots, just right before the lead one gasses him, and the nozzles come out, look closely at the bottom left of the screen (during the headshot of the lead one) and you'll see the nozzle is already out on her left breast.
Factual error: When Austin and Mrs Kensington are in the Electric Psychedelic Pussycats Swingers Club, the Union Flag in the club is back to front. The cross of St Patrick, ie the diagonal cross, should be rotated slightly anti-clockwise, not clockwise, as we see it. (00:04:35)
Continuity mistake: This mistake takes place when Austin, Vanessa, and the guard are with the mutated sea bass. When Austin judo chops the tooth paste onto the guards face, the guard is wearing a helmet and half of it has toothpaste on the front. Then the camera does a close up on Austin. When it shows the guard again, he doesn't have his helmet on and half of his forehead has toothpaste instead of his helmet.
Continuity mistake: In the scene in the toilet, we clearly see that his pants are pulled down in one shot, but then when he's drowning the Irish guy, they are suddenly pulled up again. (00:31:55)
Continuity mistake: Watch the distance between Austin and Basil Exposition just as their first meeting comes to a close. It changes from far to near and back to far in the space of a couple of shots!
Continuity mistake: Near the end when Christian Slater comes back with the orange sherbert Austin has no gun, and then in the next shot Austin has a gun but no sherbert. [There are two versions of the film - a US, and non-US version. Christian Slater appears in the non-US version in a cameo role for a couple of lines.]
Continuity mistake: When the Vulcan drill is shown being rotated, first of all, it's being rotated in the wrong direction - in the direction that would make the drill face upward. Of course they could be planning to make a 360, but why? Also, if you look closely at the people below and around the drill, you'll notice that shot is in accelerated pace - everyone is moving really fast, like in old silent films. The guys in front of the drill are looking back and forth from their pads and the drill extremely fast. I guess it was done to show the drill rotation nicer.
Audio problem: When Austin and Mrs. Kensington are shooting at Dr. Evil after he gets into his Cryogenic Freezing Chamber, in the last shot before it shows the Big Boy shooting off of the club, many sounds of gunfire are heard, however, both Austin and Mrs. Kensington have appeared to have stopped shooting. (00:06:25)
Factual error: The 1960s London policeman at the beginning is carrying a baton on his belt. British police officers didn't start carrying batons until the 1990s. Before that they only carried short truncheons in concealed pockets. (00:01:50)