Continuity: During the complete car-bomb chase sequence towards the end of the film, Michael Clayton's car is shown in one shot without its lights on. All the surrounding shots in the scene have both cars with their lights on. This is also a slightly revealing error because it shows that they actually filmed these sequences during the day using neutral density filters.

Continuity: At the end of the movie as Michael Clayton is hailing a taxi, there is a silver SUV and a moving truck behind the taxi. As he gets into the taxi, the SUV and truck disappear and there are only yellow taxis behind his own.

Continuity: When Michael is talking to his cop brother at the birthday party, his brother folds his collar up to put his tie on, and the collar's folded over at the back of his neck. The angle changes while he fiddles with his tie using both hands, then when we return to the previous angle his collar's now fixed properly.

Continuity: Throughout the entire movie there is a pimple on George Clooney's forehead. It changes size, disappears, etc throughout the movie. You will notice on some closeups that the pimple is quite large and when the camera goes away and then comes back to Clooney, the pimple is tiny - very inconsistent with how a pimple would actually develop.