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.
Other mistake: When Frank's with Margaret in her tent and she tells him that she thinks they should reevaluate their friendship, there's a Life Magazine lying on her bed which is dated over 15 years in the future - August 25, 1967, with "The other war in Vietnam" written on its cover.
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)