At the beginning, when the entire gang is in the kitchen, Kelso is eating from a box of Alpha-Bits cereal. When the camera angle changes, the cereal box reads "Ghostly Grabber". After the camera angle changes back, the cereal box again reads "Alpha-Bits".
During Fez's finger-print tutorial, when Nina presses his fingertips on the paper, no fingerprints are left behind. However, when he puts his hands on her butt, he leaves ink handprints.
When Fez touches Nina's butt he leaves whole hand prints, and later his whole hands are covered in ink. However, when fingerprinting, only the fingertips are inked.
Donna and Eric talk about when Midge left as though they were still dating at the time, but they were broken up.