The Wedsworth-Townsend Act - S1-E1
Continuity mistake: After Johnny learns of his last rescue's death, when he enters the hallway the treatment room beside the nurses' station is treatment 4, but when Brackett and Early pass the nurses' station to go save a rabbit from a sousaphone, it's treatment 2 that's beside the nurses' station. Then, as soon as Brackett and Early enter their door, in the next shot as Dix speaks to the officer, it's treatment 5 beside the nurses' station.
Visible crew/equipment: In the opening scene where General Clayton is explaining the 4077 to the psychiatrist, the scene changes to the outdoor set and the camera pans to the right. As the camera pans past the hospital, a white 1970s era shuttle van can be seen driving into the set in the upper right corner of the screen. (00:01:35)
Goodbye Mrs. Slocombe - S10-E1
Other mistake: When Mr. Humphries first comes back to the department in drag and talks to Capt. Peacock before being directed to the Ladies Dept., you can see, in the background, Mr. Spooner trying desperately (and unsuccessfully) not to laugh.
Visible crew/equipment: While the family starts packing up their car with John's suitcases and boxes, right after John says, "I just don't want any kind of a big scene," a cluster of boom mics dip into view and stays there at the top of the screen, over Mary Ellen and Jason. Then in the closeup, as John agrees that they will all go see Olivia, a crew member wearing a blue shirt (with a front pocket) is visible in the vehicle's window reflection. (00:44:40)
Visible crew/equipment: Modern tyre tracks from the camera truck are seen in the mud as Alethea waves goodbye to Kwai Chang Caine.