Continuity mistake: During the opening of the fight scene in Monaco, pay attention on the first racing car (the red one) that Vanko attacks. Even before he cuts the car's front spoiler off, the rear of the vehicle begins to flip over.
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: During the scene where the prism accelerator beam cuts through some objects, it is visible that the metal cabinet it goes through is pre-cut, and falls apart before the beam is even halfway through.
Answer: He wanted to do something nice for her, but since he is a pretty self-absorbed, shallow multi-billionaire, he forgot about her allergy. He remembered that there was SOMETHING about her and strawberries, but misremembered and thought it meant she really liked them. He makes a simple human mistake, not out of meanness or spite, but because he honestly does not remember.
Twotall