When Cheryl and Sam/Cameron are in her bedroom and she is polishing her toenails, in long shots she has no polish on her fingernails, yet when she tips the bottle over, in close ups she has red polish on.
When Sam encounters Michael Jackson in the restroom, Michael ask him who he is talking to. Children and animals can see Al. Michael would have seen Al and known Sam was talking to him.
When Sam races Bob for "pink slips", even though a car is equipped with nitrous oxide, it still runs on ordinary gasoline. The car's instrument cluster shows the speedometer climbing to 75 mph and the odometer ticking over, yet the gasoline gauge is below "Empty" and the temperature gauge is on "Cold".
When Sam looks in the mirror at the beginning, he bares his upper teeth to examine his braces. His reflection bares its upper and lower teeth.
Purportedly, Sam teaches Michael Jackson how to moonwalk. However, Michael Jackson was born in 1958, only three years before this episode takes place. The boy seen here is clearly older. He also doesn't see Al, which three-year-olds on the show can do.
Sam arrives on June 6, 1961, but the music heard at Pinky's Burgerland is Dion's "The Wanderer", released in November, 1961.
Sam arrives on June 6, 1961, a Tuesday. However, when he goes to his host body's home, an episode of Leave It to Beaver (1957) is airing. The episode Eddie's Double-Cross (1960) aired on Saturday, November 19, 1960. The show aired on Saturday nights, and new episodes aired on June 3, and June 10, 1961. No repeat aired on June 6.
There is a scene where Sam teaches a young Michael Jackson how to do the moonwalk. However, the episode takes place in California in June 1961. All of the members Jackson family were still living in Gary, Indiana at this time.
At the end of the episode, when Sam is seeing Cheryl off as she leaves to join the Peace Corps, Cameron and Cheryl's parents are inexplicably absent.