Everybody Loves Casey - S4-E26
Factual error: The gang keeps referring to the theme park 'Great America' as "Six Flags." Up until the 80's the park was actually Marriott's Great America. There is no other Six Flags theme park in the area. - from Wikipedia "Marriott Corporation began construction on the park in 1974, and opened it in 1976 as "Marriott's Great America". In 1984, the park was purchased by Six Flags Corporation, becoming the 7th Six Flags park."
Factual error: Eric makes a reference to "Sophie's Choice." This episode is set in 1978, but the book "Sophie's Choice" wasn't published until 1979, and the film adaptation wasn't released until 1982.
Factual error: Eric compares Jackie and Kelso's breakup dilemma to "Sophie's Choice...but for morons." Sophie's Choice was not published until 1979 (the movie in 1982), when this episode takes place in 1978. (02:49:00)
Answer: It's Ashton Kutcher's dog.