Other mistake: If Harry was born in 1969 and is 18 when he attends school (based on "8 years later" then "10 years later"), then the year should be 1987, not 1986 as the movie states. (00:01:25 - 00:01:52)
Suggested correction: This isn't necessarily true. The +8 and +10 years don't have to literally be to the day. Maybe Lloyd hasn't had his 18th birthday yet - it could be days away, making 1987 valid. Lloyd was born in 1969, but I don't think that was indicated for Harry. Harry was "held back 3 years", so may have been born in 1968 in order to be in the same grade as Lloyd, who was held back two years. Otherwise, Lloyd would be a sophomore and Harry a freshman, which questions how they're in classes with jrs/srs?
First off, the mistake isn't focused on anyone's age, just the date. Second, we know Harry was born in 1969 since the film starts with his, so your comments don't make sense. It says 1969 and the 8 years later followed by 10 more years later, which would put it at 1987.
Other mistake: When Lloyd asks Harry about the geeky girl, the clip of the girl is in reverse, hair shows the effect. (00:08:55)
