Visible crew/equipment: At the end, Sam gives up trying to get the phone number of the woman at the table. As Sam walks back to the bar, Cheers director James Burrows can be seen directing an off-screen camera. He is the bearded man wearing the green shirt.
Character mistake: Cliff tests Norm's memory by asking him who the bad guy in 'Herbie The Love Bug' was (presumably meaning the first movie, which was just 'The Love Bug, ' no Herbie in the title, and not the TV series that actually had the 'Herbie, the Love Bug' title). Norm answers Keenan Wynn, and is told by Cliff that is correct and that his memory is OK. Wynn was the antagonist in the second movie, 'Herbie Rides Again' (reprising his role from the 'Absent-Minded Professor'). The bad guy in 'The Love Bug' was played by David Tomlinson of 'Mary Poppins' fame.
One for the Road (2) - S11-E27
Audio problem: While Sam and Dianne are at Melville's after both of their lies have been revealed, when Dianne tells Sam that she came back on a quest for the truth, we hear Sam respond, "And you just brought along your one-man Warren Commission there," but his mouth is saying something entirely different. (00:12:15)
The Girl in the Plastic Bubble (2) - S11-E7
Revealing mistake: When Frasier is on the window ledge the safety line preventing him from falling is visible in some shots.
The Girl in the Plastic Bubble (2) - S11-E7
Visible crew/equipment: When Norm leaves the bar after seeing Frasier on TV the edge of the set can be seen. The brick wall ends and there is a curtain.
Teaching with the Enemy (1) - S11-E6
Visible crew/equipment: The studio lights are visible when Frasier is done with his scotch and says "one more, Woody."
The Girl in the Plastic Bubble (2) - S11-E7
Visible crew/equipment: After Frasier comes out of Sam's office and goes to sit at a table the studio lights and boom mic are visible. (00:13:15)
Continuity mistake: When Woody is showing Sam what he bought at the drug store a mask appears on the bar, but Woody was not shown taking it out of the bag. (00:01:00)
One for the Road (1) - S11-E26
Continuity mistake: After Don leaves the bar, a few minutes later Frasier shouts at him, "Run, Don! Run like the wind!" and Rebecca is left sitting alone at the table crying, but when it cuts to the overhead shot of the bar we see Don is still sitting at the table, even though he left five minutes earlier. (00:07:05 - 00:08:15)
One for the Road (1) - S11-E26
Visible crew/equipment: When Rebecca leaves Don at the table to relax while she gets champagne to "celebrate the answer", it cuts to an overhead shot as we hear the TV host introduce Salman Rushdie and Dr. Ruth, and the set lighting can be seen as well as the boom and mic moving around at the top of the screen. A few minutes later the mic can be seen bobbing again in the overhead shot from the same angle. (00:03:20 - 00:08:20)
Feelings... Whoa, Whoa, Whoa - S11-E9
Other mistake: At the beginning of the episode when John Hill comes downstairs he says he hasn't the bar since the fire. But he was in the bar in the previous episode.
Answer: Here is the source of the "WE WIN" photo: http://www.oldnycphotos.com/nyny587ac.html Brooklyn, of all places.