Other mistake: When all the animals visit Dolittle at his apartment and he turns on the light in the hallway, you hear a click and the lights turn on, but there is no light switch.
Revealing mistake: Dolittle's daughter is in the woods holding the cell phone talking with his dad about the dog he is bringing, but the phone screen is off all the time.
Continuity mistake: The crack on the alligator eggs keeps changing abruptly between shots, sometimes totally open, others almost closed without any logical order whatsoever.
Answer: Geno deliberately broke Mark's nose during the party after Mark made a snide remark. After the party, when Mark suggested a way to have John committed and still get their money, Geno had enough of Mark's ignorance and punched him in the nose again to add further insult to injury.