Revealing mistake: When Sonny is on the payphone, you can see Julian mouthing something to the guy on the payphone behind Adam. The guy is giving him instructions.
Revealing mistake: In the surprise party scene for Sonny at Hooters, Layla is holding a real baby and then you see her holding a baby doll. It is very obvious because there is a huge size difference between the two, and the "real" baby's head was always shown.
Revealing mistake: When Sandler is talking to the kid, they are passing through the Greenwich Village area. In the next shot, they are walking in front of a "clock building" (one side has the numbers 1-12 and 0-59). This building is located on John Street in the financial district, which is over 2 miles away.