The morning after Stewie got drunk, the family is sitting at the table for breakfast. Brian is having an egg and bacon. After Stewie falls from the shelf, Brian's plate mysteriously has two eggs and no bacon.
In the scene where Brian and Stewie are playing chess inside the Winnebago, the game board and pieces are completely unaffected by the heavy rocking of the vehicle shown in the overview shot opening the scene. On top of that, the rocking seems to have stopped completely once the scene cuts to the interior.
Tom Tucker's mustache is revealed to be fake when he is asked to turn it in along with other studio property. But in the retirement home scenes that ensue, he has it back and it has turned gray with the rest of his head hair, implying that it is real.
When Stewie runs into Quagmire's room in the motel, Quagmire is tied to the bed and his hair style is different (the style it is when Peter meets him as a sailor in the TV show). This is mentioned on the commentary.