Continuity: Before Ali G gives up his hunger strike he takes a bite out of the chicken piece and the reporter puts it back into the box. In the next shot the reporter puts the chicken piece back into the box again.

Deliberate "mistake": At the end when Ali smokes the huge spliff, look in the difference in length between when he first lights it and starts smoking it and when he starts blowing the smoke out. It's about 10 times smaller in the second shot.

Continuity: After Ali has thrown his chain at the PM and is heading back to Ricky and Dave, he bends to pick it up. In the next shot of the PM, you can still see the chain.