Iron Man is pretty good. Robert Downey Jr.'s performance is excellent, as has been widely reported, and director Jon Favreau perfectly balances the right level of seriousness with action thrills and lighthearted fun. Favreau also displays a rare knack for deploying special effects in a realistic, unassuming way that allows you to forget that they're effects (and surely it doesn't hurt that a metal suit is easier to render convincingly than a man in spandex).
Given all that went right, it seems churlish to dwell on the few nagging details that bugged me, but in a movie so otherwise solid, they stick out even more:
1. When Pepper Potts accidentally pulls out the copper magnet from Tony Stark's chest, why don't they replace it before installing the new arc unit? Isn't the arc just a power supply, and the magnet the necessary component to keep him alive? Stark explicitly warns her not to remove the magnet, and when it's out, he starts crashing, yet they quickly install the new arc without the magnet and everything is fine. You might argue that his new arc unit contains a built in magnet, but then why would he warn her not to remove the old magnet, and why wouldn't he still need it when he later re-installs the old one?
2. When Stark crawls to the basement (having fortunately not died yet during his fifteen minutes of paralysis) and re-installs the original arc unit (still sans magnet) how is he able to do so without Pepper's tiny hands to help him? Previously the movie made a point of establishing that Stark was unable to install an arc without Pepper's help, yet when the plot demands it he is able do it himself despite being in a debilitated, less-coordinated state.
3. After Iron Man wins the final battle and is lying unconscious with the arc unit about to flicker out, we cut straight to him being fine at the press conference. How did they save him? Presumably the other arc was destroyed with Obediah, which means there are no arc units left. Did the guy from S.H.I.E.L.D. just hook him up to another car battery until he could build another one?
This third point is the easiest to explain away. It's a bit of a cheat, but I can understand why for pacing reasons you don't want to pause to watch Stark build another arc unit.
However, the first two bother me specifically because the movie goes out of its way to establish that 1) the magnet is important and 2) Stark needs Pepper, or someone with small hands, to help install his arc unit, and then these points are disregarded just when you think they are going to pay off. Why even include the magnet just to ignore it? I would have bought that the magnets were in the arc units if I hadn't been specifically told otherwise. And wouldn't it have been a great, tense scene and a satisfying payoff to have Pepper racing to get there in time to help, then finding Stark unconscious with the arc in hand but unable to use it, but luckily, thanks to that earlier scene, she knows how to install it and saves him?
Did this stuff bother anyone else or am I the only party pooper? Were there explanations that I missed somehow?