Dollar bills don't easily rip apart like that.
During the driving scenes, neither Eric's nor Red's cars have rear-view mirrors.
In the empty swimming pool, Mila Kunis clearly stumbles over her lines when Ashton Kutcher holds her up in the air.
Kelso acts nervous while he picks up a tap from the liquor store. But, it is revealed later in the series that Kelso was held back as a kid, and is a year older than the rest of the group. That makes him 18 years old, the legal drinking age in Wisconsin at the time. Kelso should not be nervous, since he knows he's of legal drinking age. He consciously kept this secret from the group out of fear of ridicule.