Two Flew Over the Cuckoo's Nest - S6-E7
Corrected entry: In the scene where Jack and Janet are sitting on the sofa with the doctor, Janet offers the doctor some nuts from a bowl. Then take a look at Janet's face. She begins to laugh so she lowers her head and the camera immediately shoots over to Jack who realizes the goof and adlibs something to give Janet time to get into character again.
Jack Bares All (a.k.a. Oh, Nurse) (2) - S6-E2
Corrected entry: When they're getting ready to make fun of Teri, and Jack is going to press the glasses onto Teri's face that leaves the rings under her eyes, he calls her "Tammy."
Correction: Jack is being as overtly obnoxious as can be, and the "Tammy" was quite deliberate on his part. Jack also did not pronounce Terri correctly, but instead pronounced it like "Teary" just to emphasize the obnoxious behavior (when Jack feels bad while holding the seltzer bottle he pronounces her name correctly).
I respectfully disagree with that synopsis - being obnoxious doesn't mean you purposely mispronounce a name. Seems that if it was on purpose, one of the cast (in character) would have corrected him. Some things slip through editing due to time frames and reshoots.
Correction: This has already been submitted and has been sitting in the corrections section for some time with a few different answers. Nobody knows the real answer but some good possibilities have been submitted.
Jack Bares All (a.k.a. Oh, Nurse) (2) - S6-E2
Corrected entry: In the party scene, Jack and Larry give Terri glasses to put on that give her black circles under her eyes. Jack calls Terri Tammy when asking if she's been getting enough sleep.
Correction: Jack is supposed to call her Tammy because he is trying to get rid of her.
Correction: That reasoning doesn't sound right. He was trying to get rid of her-yes, but it seems more likely John Ritter simply made a mistake in the script but it was not spotted or corrected due to the fact the producers of the show rarely allowed retakes so many ad-libs and errors were sometimes left in.
Correction: I agree this mistake is valid. While there was a line in the beginning where he jokingly says "what's your name again", that was part of the act as if she was a random volunteer. But then he calls her his "lovely assistant, Teri", then called her Tammy, but then once again calls her Teri during the "act", before he shot ink on her dress.
Correction: On the DVD set of this episode (which I doubt is different than what aired, but I could be wrong), after Janet offers the "nuts", she hangs her head in shame. The camera does not shoot over to Jack, instead Janet goes into some dialogue about how she shouldn't have said said a thing and instead asks if he'd like cheese. During this time, Jack says nothing to either of them until he tells Janet "Good job!" for getting out of the situation, and tells Janet to not offer any more nuts and to not offer crackers.