Continuity mistake: In the beginning, The Statement is being typed on a manual typewriter and the name Pierre Brossard is underlined except for the letter P. The next time we see The Statement, the letter P is now underlined. There is only one copy.
Continuity mistake: After Johnny and Mark return to the rooftop following the "Chris R." sequence, we see Johnny run into frame, and Claudette is standing by herself to the side of the others. Mark is not on the roof yet. Immediately after during the next few shots, Mark suddenly appears behind Claudette, and even has his hands on her shoulders.