When AJ shows the three guys his drums he has short hair, cut above his ears, but when he's on the boat with Tony, his hair is long again.
At the nightclub, AJ has an earring in his right ear. When he falls in the bathroom the earring is gone.
When Tony and Julianna are discussing psychological techniques for contract completion, Tony picks up Julianna's pen and plays with it. The camera then cuts to a close-up shot of the contract pages, showing the pen still resting on top of the paper.
When A.J. and Tony are shooting the breeze on their fishing trip, the position of the handle on Tony's reel changes between shots.
Tony agrees to sell the market to Jamba Juice after the offer from Julia increases. When they are signing paperwork for the sale at her apartment, one of the documents she presents him to sign is a Deed of Trust. Since the property is located in New Jersey, this is the wrong document to collateralize the property. In New Jersey, and in most northeastern states, the correct document is called a Mortgage. What's more, Tony is the seller and would not be called on to sign the collateralizing document--that's for the buyer.
The receipt for the club didn't show that they charged an entrance fee for AJ and his friends even though all high-class clubs in New York City charge the entrance fee separately. The entrance fee is charged immediately when the patrons first enter the club.
When AJ and his friends go to the nightclub it is clearly nighttime. When they are presented with the bill for 2 bottles of Cristal and 1 bottle of Grey Goose, the receipt has a time-stamp of 2:34 pm.