Continuity mistake: When Gino and Arliss are given the contract to kill Agent 11, note the distinctive pattern on the shirt Arliss is wearing - particularly the collars, which keeps changing even within the same scenes. Though the actor's wardrobe consisted of black shirts of the same style, their patterns varied. For example, during the scene at the pet store there are at least three different patterns seen on his shirt. The same thing happens again later with a different shirt Arliss is wearing, after the scenes of Gino and Arliss at the dog training facility.
Continuity mistake: When Gordon fixes himself the bowl of bran cereal with soy milk and prunes, he places the orange cap back on the soy milk, but when he tries to eat the cereal and spits it out, the soy milk cap is gone. Then it's back on the bottle, before it's off and back on again. (The regular milk cap is pink).