Character mistake: When Alex mentions to Mallory that he's had sex before, he tells her he was 17 and that it was leap year. Not correct, this event occurred in 1982 (during one of the first episodes when Alex was 17), which was not a leap year.
Character mistake: The sign in front of the tank Lt. Ladd is trapped in reads "ORDINANCE TESTING FIELD, DANGER.", but an ordinance is a type of decree or law. They probably meant 'ordnance', which is another word for artillery.
Character mistake: Cliff tests Norm's memory by asking him who the bad guy in 'Herbie The Love Bug' was (presumably meaning the first movie, which was just 'The Love Bug, ' no Herbie in the title, and not the TV series that actually had the 'Herbie, the Love Bug' title). Norm answers Keenan Wynn, and is told by Cliff that is correct and that his memory is OK. Wynn was the antagonist in the second movie, 'Herbie Rides Again' (reprising his role from the 'Absent-Minded Professor'). The bad guy in 'The Love Bug' was played by David Tomlinson of 'Mary Poppins' fame.