Other mistake: Nicole is through a window of the house in the scene when Darwin asked "Which one is the real Gumball?" This is probably from the episode "The Goons." (00:00:05)
Audio problem: When The Butterfly lands on one of the construction workers, he says "Get it off!", but his mouth doesn't match the movements.
Continuity mistake: After Gumball stops crying, there are still tears on his face. In two shots, the stream of tears disappears.
Other mistake: When Gumball tries to comfort Alan, Alan opens the door but Alan is a balloon, with no hands to open a door. (00:04:35)