Continuity mistake: When Woody gives Norm a beer he puts a napkin next to the beer. The shot changes the napkin is under the beer.
Continuity mistake: During the scene when Norm is giving Doris the letter of recommendation her hair his covering her ear facing the camera. When she says "It must have taken a lot of guts to open up that way." Her hair is now behind her ear.
Where Have All the Floorboards Gone? - S10-E8
Continuity mistake: After Kevin leaves the blueprints on the bar go from unrolled to rolled up a couple of times between shots.
Where Have All the Floorboards Gone? - S10-E8
Continuity mistake: In the opening scene when Frasier's car alarm keeps going off two people are walking behind him heading to cheers. In the close up of Frasier they are not there.
Continuity mistake: The second time Frasier and Lilith come into the bar Sam is putting ice in glasses for them. Sam finishes the second one and puts it on the bar. The shot changes he is still putting ice in the second glass.
Fools and Their Money - S4-E12
Continuity mistake: When Sam asks Woody to go into the office to talk privately, Woody has no apron on. As they walk in to the office, Woody has the apron on, which then disappears.
Continuity mistake: In the back room, Norm's glass goes from nearly empty to half full and back.
Continuity mistake: When Rebecca and Sam are talking about the auction in one shot the beer in front of Norm disappears. (00:03:25)
Continuity mistake: Sam puts a beer in front of Norm. The shot changes and Sam repeats the action.
Continuity mistake: At the beginning of the episode when Diane and Sam are talking, Sam is pouring some coffee, he starts to put the coffee pot down, the shot changes and he is no longer holding the coffee pot and has started to pick up his cup.
The Peterson Principle - S4-E18
Continuity mistake: When Norm says "you're right, guys don't tell on other guys" the cigar he is holding suddenly moves to the beer mug in front of him.
Continuity mistake: When Sam goes over to talk to the guy sitting at the table, the door opens and someone walks in, the shot changes and the person has disappeared.
Birth, Death, Love and Rice - S4-E1
Continuity mistake: Sam puts a empty champagne glass in front of Norm, the shot changes and the glass is now full.
Continuity mistake: When Diane picks up Carla and puts her on the bar stool, Carla puts her hand in her lap. The shot changes and her hands are now on the bar.
Sam Turns the Other Cheek - S3-E5
Continuity mistake: The gun that Marvin puts on the table changes position a couple of times.
Continuity mistake: Emily is sitting at the table with a beer before Norm brings her one. (00:07:10 - 00:08:00)
Continuity mistake: When Sam and Diane are talking about what they are going to have for dinner Sam opens a bottle of wine. The shot changes, the wine bottle has disappeared, and Sam is holding a couple of glasses. (00:14:15)
Old Flames - S2-E7
Continuity mistake: After Dave walks into the bar the amount of beer in Norm's mug changes a couple of times.
Let Me Count the Ways - S1-E14
Continuity mistake: When Coach introduces Marshall to Diane, there is a beer mug in front of Marshall, the shot changes and he is now holding the mug. The next shot the mug is on the bar, when the shot changes again he is holding the mug.
Let Me Count the Ways - S1-E14
Continuity mistake: In the opening scene Diane picks up a towel that is on the bar, the shot changes she is no longer holding the towel. (00:00:25)
Answer: They sometimes acquire episodes from syndicated reruns. The ones with the cut scenes. Sundance channel have some episodes of M.A.S.H. uncut.