Revealing mistake: About 1/3 through the episode, they are in Roz's apartment. If you watch when people enter or leave the apartment, the door has a handle lockset. It also has a lock cylinder about 1 1/2 feet above it on both sides of the door. The problem is, the side of the door has no drill hole where the latch assembly should be: it's just solid wood. The lock isn't attached to anything that would enable it to work.
Revealing mistake: The guy who plays Clive in this episode has one of the most appalling accents I have heard. He's apparently from Manchester, but sounds like a sort of cockney South African. His accent slips around all the time; it's very poor. I wouldn't normally submit it, but his is so shockingly bad I doubt anyone would be fooled into thinking he was British.
Revealing mistake: When Reagan drops her bag in the hallway when she is talking to Frasier, a lettuce rolls towards him. It didn't fall from her bag: if you look closely you can see it was tossed into the frame from just outside the camera view, obviously to ensure that it would land at Frasier's feet for the comic effect of him kicking it back to her.
Revealing mistake: The view from Frasier's apartment shows the Space Needle prominently in the background, however, the elevator that takes visitors from the ground to the observation deck is frozen in time midway to the top. This was corrected after the first season.
Revealing mistake: At the end of the episode when Frasier reveals to everyone that Roz is the one who's pregnant, we see Peri Gilpin step into the shot at the top of the stairs too early. She steps back behind the wall and then walks back out again a second later to say her line.
Revealing mistake: In the scene where Frasier and Lilith meet in the living room, where Frederick has created a romantic atmosphere, Frasier has a long speech about how Lilith is not going to get him back, ending with "I need to be finessed!" and Bebe Neuwirth goes out of character and begins to giggle, before she quickly covers her mouth and pulls herself together. Though Lilith might have found Frasier's comment amusing, it would definitely not be in character for her to giggle like that.
Revealing mistake: Frasier comes in complaining how workmen in the service elevator have dribbled chili dog on his foot. He is holding out his shoe saying "How ever will I get that stain out", and Eddie runs over and starts licking what we think is the shoe. Frasier makes a comment about dog saliva being the universal solvent. In fact, Eddie does not even touch the shoe, but licks the floor in front of Frasier. Obviously the floor was treated with something Eddie would enjoy licking up.
Revealing mistake: I think there might be something wrong with the eels in this episode. They don't move in the tank, despite being alive and don't move when taken out either. Moreover, you cannot actually see any in the tank with one exception. Rubber replacements not up to standard obviously.
Revealing mistake: You have to be very quick to spot this, but when the cannon goes off Niles drops the ring, you can actually see it drop between Eddie and the camera and bounce away from Eddie. In other words, it certainly doesn't go anywhere near the pate.
Revealing mistake: At Cafe Nervosa, after Niles has had a mini-breakdown, he has shed his clothes, boxers and all, all over the place and is supposedly naked in the corner with only a newspaper for privacy. When Frasier has him stand up to wrap aprons around him, one can see that David Hyde Pierce is actually wearing light-coloured briefs.
Revealing mistake: Near the end, in Cafe Nervosa, the guy that wants to sue Frasier gives Niles a push. Niles stumbles backwards, knocking over some chairs and the coat rack before falling down, taking the table by the window with him. If you look closely just before he hits the table, the woman sitting there (rather than moving out of the way), very subtly pulls on the table, so as to upend it so Niles can go down with it.
Revealing mistake: During the scene where Frasier is dropping Charlotte off at the train station (the first time) you can see the background behind him shows that the car they are in is turning left. Yet we can see his hands on the top of the steering wheel and during this time he never turns the steering wheel.
Revealing mistake: Bebe is in the booth telling Frasier how she misunderstood him about Roz. As she says "wink", we can see Frasier's reflection in the booth's glass - his head bobs up. The next shot we see, though, is of Frasier's head bobbing up - shot at the same time, we just see it a split second later.