So they shoot the scene, Bond's hands look amazing, and months later, they're editing it and suddenly realize what a colossal mistake they've made. Earlier in the film, they'd gone to great lengths to establish that Bond had a gun with sensors that read his fingerprints so that it wouldn't work if anyone else tried to fire it. There was a whole big scene with Q when they introduced it, and the gun not firing for some thug in Macau is a key plot point. But if that's the case, then how the hell would the gun work when Bond was wearing gloves?
We should point out that this anecdote hasn't been confirmed by anyone official. But the evidence for it is substantial. Check out this production shot distributed before the movie was released to see Bond during the Shanghai sequence with both the gun and the stupid frigging gloves:
Yeah, that's not going to work. As the story goes, when they realized the problem in post-production, they knew that none of the solutions would be easy. Most of them would have required re-shooting hefty chunks of the film. What they eventually came up with (throwing computers at it) more or less solved the problem, but it's hardly perfect. They CGI'd Bond's hands back into all the scenes in which he was wearing gloves, which means that if you pause during the right scenes, you can see Bond sporting some damned puffy-looking hands.