Factual error: In this film, and in Raiders of the Lost Ark, the German vehicles are marked with the DAK (Deutsches Afrikakorps) symbol (a swastika over a palm tree.) The DAK and its symbol were not created until 1941 when Hitler tried to rescue his Italian allies in North Africa. (00:56:15)
Factual error: When the air hose on the truck is severed, the brakes release. In reality, on an air-braking system, if the air hose is severed, the brakes lock on as a safety measure.
Factual error: [Special Edition] The Statue of Liberty is incorrectly shown to be facing the Narrows bridge.
Factual error: When Bill and Ted grab Beethoven, we are shown the piano he was playing which is a Steinweg (Steinweg later changed his name to Steinway when he immigrated to the United States). Steinweg made their first piano in 1835, and the model shown was built in Braunschweig so must have been made after 1858, but Beethoven died in 1827, years before a Steinweg piano existed. Also the onscreen graphic says it's 1810. (00:47:50)
Factual error: Marty is pursuing Biff at the high school as the other Marty pulls up with Lorraine in Doc's car. In the parking lot, the car closest to Biff is a brown 1957 Chevrolet. The front grill and styling are distinct and unique to the 1957 model year. In November 1955, it would be plausible to see a 56 Chevy in the lot, but a '57 is a bit early. (01:16:42)
Factual error: In the lunch scene outside their office, Larry and Richard are at the food stand and notice Bernie walking into a building. The entrance awning reads "East 70th Street". As they walk away the street sign behind them reads "52nd Street". Apparently they must have superhuman vision which allows them to see 18 blocks away.
Factual error: After their parents give up looking for the kids, there's a "time passing" scene showing the lit attic window from the outside of the house, in which the night grows lighter until it's morning of the next day. But the moon in the picture doesn't move. How can the moon stand still if time is passing?
Factual error: During the match Mimi has Lisa on the ropes choking her too long. The referee would've counted to five then disqualified her when she refused to break the hold.
Factual error: The girls need to pay $7.50 for 36 badges. However, badges are usually paid for by the leader out of the weekly dues money, and at $10 a week, and not needing to pay for a weekend meeting place (they seem to meet at her house most of the time), they should have plenty of money to pay for them.