When Brian first gets shrunk by Stewie, he is seen standing (solidly) on top of the carpet. Though when Stewie shrinks himself to rescue Brian from the Rat, both are then seen leaving the rat hole walking waist deep within the carpet pile. This was not the case, when Brian was about to be caught by the Rat & taken to the hole in the wall.
When Girly Friendston's mother (not shown) is supposed to be speaking to her daughter, no dialogue is heard.