Character mistake: Brock states that the Diglett are plowing the ground and the Dugtrio are planting the trees, but the opposite is true (The Dugtrio are plowing, and the Diglett are planting).
Little Box of Horrors - S7-E18
Character mistake: Katya (as Nina) says that Pandora's Box is "a gift the gods gave to Prometheus." But the Box was given to Epimetheus, not Prometheus. Epimetheus ignored the warnings of Prometheus, his brother, and accepted Pandora herself, who bore a box, as a gift from the gods.
Character mistake: In the opening scene, Doug call Carrie "Kel" which is Deacon's wife. He calls her that when he's saying they should just get a new grill.
Character mistake: When Charlotte is looking at her wedding announcement in the New York Times, there is a close-up shot of part of the article. It says, in reference to Charlotte: "She is a writer and editor at Fashions Magazine in Manhattan". This is not true, nor has it ever been true. Perhaps the producers of the show threw that in, to see if anyone would notice. Also, the same article mentions: "The bride, who will be keeping her name..." and yet we never really hear Charlotte use the name York instead of Goldenblatt. (00:16:45)
Champion vs. Creator, Part II - S1-E27
Character mistake: Pegasus says his toon world cannot be penetrated, but that is not true since it's a magic card, so any card that destroys magic cards can destroy it. Furthermore, monster special effects can also destroy it.
Character mistake: When the gang is watering the horses, Chris walks over to meet Mary's man friend (whom she introduces as an old friend of the family) and the mystery man tells Chris that he'd proposed to Mary long before 'Frank' when Mary's late husband was Steve.
Character mistake: When talking to Will on the phone, Grace misuses the term "pied-à-terre" (which means "apartment" in French) instead of "pas de deux" (a dance for two) while describing the delicate and complex nature of a relationship between two gay men. When Will points out her error, she says she knows what pied-à-terre means because she took Spanish in high school. However, in season 1, episode 20 ("Saving Grace"), Grace correctly and easily used the term pied-à-terre while showing her sample book to a potential client.
Lovelines (aka The Eddie) - S6-E19
Character mistake: In the scene when Dr. Drew has Joey and Eddie on stage, they are arguing and Joey says that Eddie moved away and dumped her twice. Actually, he only dumped her once, when he moved out of his apartment and back home with his parents. The 2nd time that Joey is referring to is when Eddie moved to California for the writing workshop, which SHE helped and encouraged him to do. So he did not dump her 2 times; she basically pushed for him to leave the 2nd time, yet she acts as though this situation never occurred.