When they retrieve Animal from the anger management therapy and the patients start fighting each other, one of them (the tall man with short, white hair standing behind the therapist) is clearly not hitting anything, as his punch misses his opponent by at least one foot. Yet, we hear the punch and the other man falls down.
Miss Piggy makes a minor French error when trying to order the other Muppets out of her Paris office. She says "depeche-toi", which is the phrase for making an order to a single person. To make an order to a group, she should have said "depechez-vous". Of course, Miss Piggy's French skills may not be great.
During the "Me Party" scene, Mary sits at a table, tears a roll in half, and puts a fork through each piece before making them "dance" like legs. When she stands up a moment later, the silverware is seen lying on the table, without the pieces of roll.
When The Muppets plead Tex Richman to return their theatre, the establishing shot shows the Bank of America Center in Los Angeles as the headquarters for "Richman Oil". However, the same building can be repeatedly seen outside the office's windows when Richman performs his song. The scene was actually shot inside one of the towers of the nearby City National Plaza.