The Wedsworth-Townsend Act - S1-E1
Other mistake: At the start, on the way to the structure fire one of 10's rigs has license plate number E180174, but at the fire we see 127's engine has the same license plate number E180174.
Goodbye, Farewell, and Amen - S11-E16
Other mistake: How did Hawkeye Pierce, a surgeon, know how to drive a tank? It is nothing like driving a car and takes skills, training and experience that a surgeon simply would not have. He wouldn't even be able to start the engine.
The Thanksgiving Story - S2-E10
Other mistake: During John-Boy's entrance exam at Boatwright University, when he's given the pamphlet and history test questions, note three of the questions include the contraction "it's" which is incorrect within those given questions. Each question should have used "its" without an apostrophe. Additionally, the sign on the University's wall reads "keep your eyes on you own paper" instead of "your own paper." (01:00:35)