Doug's Shock Therapy / Doug Is Hamburger Boy - S3-E11
Plot hole: Doug recalls previous years (in a flashback, where he was next to Skeeter at the window of the Honker Burger as they looked outside) of seeing the Hamburger Boy when Mr. Dink is confessing that he *was* Hamburger Boy. However, Doug has only been living in Bluffington for one year - this was his first summer there.
Explorers on the Moon: Part 2 - S3-E12
Plot hole: In the flashback, Wolf wakes up to find out Jorgen is in his bedroom. The problem is Wolf wakes up before Jorgen even enters the bedroom.