Other mistake: After the turkeys start attacking in "The Running of the Turkeys", Mr. Fishoder and his brother start running. In that clip a Turkey pops out the side of a guy's head. Look in the mid lower right side. Looks like a design error. Pretty big error, no slow down needed to see it. (00:05:20)
To Touch a Hummingbird - S2-E10
Other mistake: Chris gets on the zip line and hooks up. Martin just stands behind him, not hooked up to the zip line. Chris zooms off down the line chasing the hummingbird. A few seconds later, Martin is suddenly on the zip line also and right behind Chris.
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)
Misty's Magical Mix-Up!/Bone's Lucky Doubloon - S2-E31
Other mistake: In the episode "Bone's Lucky Doubloon," Captain Hook, Smee and another pirate are washed downstream, go over a waterfall and land in a lake. When they emerge from the lake, no water is dripping from them.