When Sally grabs her piggy bank to check how much money she has, the lamp on her night stand shifts by itself.
When Goliath asks what "canine" means, various studio equipment can be seen shifting in the reflection of the meat market window he is standing in front of.
Davey tells Goliath that the "old and green" piece of paper is a ten dollar bill and Goliath recognizes it as such. However, it is established in many episodes that Goliath can't read, so he shouldn't be able to know.