Revealing mistake: When William and Jack open the door, enter the room, and walk past the helium-filled balloons (tied to a chair about 4' away), the balloons remain immobile. Due to how light helium balloons are, just opening the door or breathing nearby would be enough to cause the balloons to move somewhat - if they were actually there. (00:16:00)
Factual error: When they were driving away from the bar, neither Zoe (driver) nor Breslin fastened their seatbelts. Seatbelts are mandatory in New York for the driver and passenger (s) and failure to "buckle up" is classified as a primary offense, meaning no other violation must be observed before police can stop and cite violators. (00:57:25)