Just before Homer tells Marge that Skinner has cold feet, we see an exterior shot of the house with Homer's car in the driveway. After he does, he then asks Marge if he can use her car, "because mine's acting up." Then we see Homer's car through the bay window, upside down and aflame.
When Skinner is at the bar in a close up he drinks his whole glass of beer then puts down the empty glass. Then in the next shot he immediately has a full glass in front of him. He later drinks the beer and puts the glass down again and as the shot changes the empty glass disappears completely.
At the Bi-Mon-Sci-Fi-Con, Milhouse mispronounces Matt Groening's surname as "Groaning". The correct way to pronounce his surname is "GRAY-ning."