I just watched "Fracture" (a fantastic movie, btw, in my humble opinion), and was thoroughly convinced by everything. I thought it was (almost) flawlessly constructed. Except for one thing.
How in the world could Crawford have known ahead of time that Nunally had the same gun as him, in order to be able to go to his house and make the switch on the day of the crime? This is a serious plot hole, in my opinion, as the gamble that the gun would be the same is near impossible. This is information that would have to have been obtained ahead of time.