Continuity mistake: When Rick Walker is in the bar with Sam, he recognizes Coach as a former pitching coach for the Boston Red Sox. Yet in future episodes of Cheers, Coach is always identified as a former third-base coach.
Visible crew/equipment: When Sam, Carla and Diane are in Sam's office and begin laughing Coach walks in, laughs for a few seconds, and leaves. Right after that the obvious shadow of a piece of equipment (probably a camera) passes across the floor in front of Diane. (00:22:15)
Friends, Romans, Accountants - S1-E7
Continuity mistake: The distance between the candle and apron change between shots as Norm talks to Sawyer. The apron also changes the way it is folded between shots. (00:17:50)
Friends, Romans, Accountants - S1-E7
Audio problem: When Norm goes to leave the bar to plan his toga, a smack sound is heard just as he passes Cliff. There was nothing there that could have made the smack sound. (00:06:30)
Continuity mistake: When Carla says to Diane that Sam is the father of her son, after Diane says "You plucky little soldier, you" her head is facing Carla. Shot cuts and she's instantly half way through turning her head. (00:10:30)
Visible crew/equipment: The very first shot after the opening titles shows cars driving in front of the bar. If you look at a brown car that drives past, you can see the director sitting in the director's chair, reflected on the car. (00:03:00)
Give Me a Ring Sometime - S1-E1
Visible crew/equipment: When Sumner goes to the back to make a phone call, we can see a crew member sitting on a wooden chair with a camera beside him and a few more people in the distance. (00:04:30)
Let Me Count the Ways - S1-E14
Continuity mistake: When Diane turns the TV back on for everyone to watch the game, the TV appears in the background and it's off - this happens twice.
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)
Continuity mistake: When Carla says "And I will be your slave for the evening" she has a towel over her shoulder. When Diane goes over to talk to her it's gone.
Continuity mistake: When Diane finds out that Gino is not Sam's son, the towel that is on Coach's shoulder keeps changing position. In one shot it disappears then when the camera is facing him half is in font and half in back. When the camera is to his back most of the towel is in the back.
Continuity mistake: When Norm tells Dave he is the best sports reporter in town Dave is holding sunglasses and a paper. The shot changes and he is now only holding the paper.
Continuity mistake: When they are talking about Ed coming to the bar. Coach is drying a glass, the shot changes and he is no longer holding the glass.
Sam's Women - S1-E2
Continuity mistake: When Carla is explaining to Norm why there are drawbacks to dating beautiful women, the amount of beer in Norm's glass changes a couple of times.
No Contest - S1-E18
Revealing mistake: The photographs and news items relating to the Boston Barmaid Contest have been clumsily pasted onto a real newspaper. The paper upon which they were printed is cleaner and whiter than the off-white newsprint and the photographs have much greater contrast.
Continuity mistake: When Sam tells everyone it's closing time, he asks Harry how he got into the bar whilst he is playing snooker. He replies and then places a white snooker ball two inches behind a blue ball. There is also a yellow ball about three inches to the right of the blue ball. In the next shot, the yellow ball has suddenly moved a foot away from the blue ball. The yellow ball returns to its original position three inches away from the blue ball in the next shot. (00:00:10)
Continuity mistake: When Carla comes to the bar with her shrink, the lights aren't reflected in the door as they usually are. The lights are suddenly reflected on the door a further two shots later. (00:18:00)
Sam's Women - S1-E2
Continuity mistake: Just after Norm says "This man knows his animal kingdom" he looks at his watch and there's nothing in the other hand. In the next shot, his hand is suddenly on his beer glass. (00:20:40)
Continuity mistake: When Coach is talking to Rebecca for the first time he is suddenly drying a shot glass then it disappears.