During the end beach scene at the end of the movie Rose's hand position changes between camera angles. Her hand is by her face, then elsewhere, then by her face again.
During the conversation between Roger and his wife at the door of her room, the door changes between half open in the scenes shot from the hall, to wide open in the scenes shot from inside the room.
When George McLendon (William H. Macy) says he was part of the third wave that invaded Grenada, he shouts "Viva Grenada libre!" in Spanish, a language that is not spoken in Grenada.
At the end of the movie they are supposed to be on Miami Beach, but the background clearly shows hills and geography that is not Florida.
Even if the paintings were perfect copies, the guards had no way to duplicate the backs, in particular any stamps, labels, etc.
George served as a Marine, but repeatedly uses "Soldier" when communicating with Roger and Charles. Members of the US Army are Soldiers and no Marine would use that term unless they were referring to a member of the Army.