Factual error: 2016 special - You Can't Teach An Old Dog New Tricks: Mr Harmon comments on a perfume called Belle, which he thinks is called "Belly", "I wonder what the next one will be called. Bingo Wings?" The episode is set in 1988 and the term "bingo wings" didn't exist before the 1990s. (00:10:40)
Continuity mistake: The Gentlemen's and Ladies' Department is on the first, third, or fourth floor of Grace Brothers, depending on the episode.
Other mistake: The gender of Mrs Slocombe's cat is always different in each episode. Sometimes her cat is a female and other times it is a male. (eg. In 'Mrs Slocombe Expects', her cat is female. In 'No Sale', when Mrs. Slocombe complains about her having to get up to have a bath at 6:00 in the morning, she says, "The gurgling of the tank woke him up.").
Other mistake: There is another counter on the floor, to the right of the stairs, that is usually staffed by two women besides Ms. Brahms and Mrs. Slocombe. But throughout the show when there is a on-floor meeting for the entire floor staff, these two are never included in the discussions.
Continuity mistake: The set up of the canteen changes from episode to episode. It is never the same way twice.
Continuity mistake: If a character says their assistant number throughout the show, they are different each time.
Continuity mistake: Sometimes Mrs. Slocombe has discretion over both inventory and displays and what they will and will not sell in the ladies department, other times its Captain Peacock, Mr. Rumboldt or others that have the final say.
Other mistake: Pilot episode Mr. Lucas is holding the mannequin together with Miss Brahms. Mr. Grainger walks by and is appalled by the state of undress of the figure and says "Well, it's hardly sufficient, is it?" You can see the camera getting randomly out of focus in a bad, noticeable way. (00:03:20)
Character mistake: Mr. Lucas got himself in an embarrassing situation 'straightening the seams' of Mrs. Slocombe. Humphries passes by saving him by telling him that Mr. Granger wanted to talk to him, but he does it by saying "Griffin wants you." Wrong name. (00:07:45)
Audio problem: When Young Mr. Grace arrives, the sound department misses his first "Good Morning", which is audible only very faintly towards the end. (00:15:35)
Other mistake: When Mrs. Brahms is talking to Mr. Granger, Wendy Richards' voice cracks stifling laughter when she says "Mrs. Slocombe didn't like to take down your trousers without asking you first." (00:18:00)
Revealing mistake: When Mr. Lucas goes to "knee" the pair of pants, the pants already have the hole in them, and his knee doesn't rip anything.
Camping In - S1-E4
Revealing mistake: Mrs. Slocombe enters her tent after telling Captain Peacock about the top window. Peacock then obviously uses that moment to stand on his tiptoes and peek in. You can see to the right of the tent the metal cart pushed by Larry Martyn discreetly peek out of the stage entrance and stop as he waits his cue to come on the set, to a rumbling noise. (00:13:35)
Camping In - S1-E4
Other mistake: The episode takes place on March 2nd, 1973 (date of the newspaper shown by Mr. Mash), but in Mr. Rumbold's office the sale chart for the month of March is already fully filled up.
His and Hers - S1-E5
Revealing mistake: On the tape player that the sales girl is using, the reels are moving in opposite directions, the tape can't play doing that.
Continuity mistake: Mrs Slocombe is showing a bride a veil and puts it on the counter, but in the next shot she is still holding it and puts it down again.
Cold Comfort - S2-E2
Revealing mistake: In the very beginning of the episode you can see Mr. Grainger sitting in a chair to the very far left, with his head down, waiting for his cue to walk-on.
Cold Comfort - S2-E2
Other mistake: At the very beginning you can see a girl in the background with long hair, pausing to speak and gesture to someone off stage, before she removes the sheet draped over the counter.
Revealing mistake: When the gentleman buying the dress comes out from behind the curtain in the change room, you can see the set for the canteen, with the lights off. (00:14:45)
German Week - S3-E6
Revealing mistake: When Mr. Humphries and Mr. Lucas make their toast with the German mugs, Mr. Lucas' mug breaks but Mr. Humphries' does not. A moment later, when Mr. Humphries notices the mug has not broken, you can see that he crushes the mug with his hand.
Answer: In minstrel shows there was also a stereotype of black men preying on white women, so that's probably why she was not in black face. Also, Mrs. Slocombe is in blackface because she is an older, stout woman and she fits the "mammy" stereotype.