The year in the show is 1980, the first graphing calculator was made in 1985 by Casio. Yet some of the mathlete students are heard commenting about Texas Instruments and passing around a graphing calculator. Texas Instruments didn't start making graphing calculators until 1990.
When Cindy arrives at Sam's table in the cafeteria to borrow a pencil, Harris Trinsky is seen holding a copy of the Dungeon Master's Guide. The cover of the book shows the 1983 reprint version, though the show takes place in the year 1980.
Sam is seen dancing in front of the mirror while the song "Flamethrower" by The J. Giels Band is playing. This is impossible since the episode is set in the spring of 1981 and the song "Flamethrower" from the album "Freeze Frame" wasn't released until October of 1981.
The premise is that Lindsay was at fault for an accident while driving her parent's car. However, the accident happened because another woman backed out of her driveway into oncoming traffic. The majority of fault lies with the other driver, not Lindsay.