Continuity mistake: In the scene where Mickey Rourke is in the laboratory discussing how long it will take him to reproduce the robots, his glasses change position from him wearing them to not wearing them throughout the conversation.
Continuity mistake: When Ivan climbs the ladder to inspect the Hammer prototype, his hair changes repeatedly from underneath the frames of his glasses to outside the frames.
Continuity mistake: The scene in the Monaco lounge when Tony Stark and Justin Hammer are sitting down at a table with Christine Everhart to give an interview, Hammer sets his drink on the table while he's standing but then the shot immediately cuts to him sitting down with the drink still in his hand.
Continuity mistake: Before Hammer starts eating dessert (and thus much before the "moving spoon and cherry" continuity mistakes), there's a back angle where he dips his spoon into the dessert and starts eating. The angle cuts to a front view with the spoon laying spotless on the saucer, and Hammer saying "I'll start with dessert", and then repeating the whole previous scene as if it were the first time.
Continuity mistake: In the beginning when Tony's press conference is on TV in Anton Vanko's home, the dialogue exchange between Tony and Christine Everheart has more talking than that same scene in "Iron Man" at the end. In "2", Christine mentions that Tony hates body guards in the exchange, but, this is never said in the first "Iron Man".
Continuity mistake: After the core is removed from Whiplash during the race scene, a stream of blood visibly trails from the corner of his mouth. The shot changes to him spitting and the blood is gone. The shot changes again and it reappears.
Continuity mistake: During the Monaco part of the film,when Hammer and Christine Everhart are talking at the table and the camera is angled towards her,Christine is holding her phone in her right hand and her recording device in her left. When the camera changes angle to face Hammer and Christine stands up to leave,the phone and recorder change hands.
Continuity mistake: When Whiplash and Hammer are in the hanger, the butler comes in and removes the same thin wine glass twice. Other glasses disappear and reappear and move position between camera angles. Also one glass fills instantly between shots with water when no-one was nearby to fill it.
Continuity mistake: When Mickey Rourke is introduced to Sam Rockwell, they sit down for a rather lavish lunch in the Hammer aircraft hangar. As Sam drones on in his introductory remarks, the camera watches a waiter starting to pour red wine into the glass directly in front of Mickey Rourke. The camera cuts back to Sam, and Mickey's wineglass is already full. Camera cuts back to Mickey, and the full wineglass has moved about a foot to Mickey's right, although he hasn't touched it.
Revealing mistake: Just after the scene where Tony meets Justin Hammer, Tony is looking at himself in the bathroom mirror and the supposed 'mirror' Tony raises his hand to suck on his bleeding finger. However, we can see the back of the also supposed 'real' Tony, he also raises his hand as the camera zooms into the mirror, but his hand movement is much later than the hand movement of the 'mirror' Tony. Therefore proving that both Tony's are two completely different actors so when zooming in, the camera could create the illusion of a mirror without the camera filming itself.