Quarantine - S5-E4
Visible crew/equipment: When Rimmer asks the crew if they had forgotten Red Dwarf could only sustain one hologram, it shows a shot of the rest of the crew who say nothing. At the top of the screen, a boom mic can be seen. (00:03:00)
Quarantine - S5-E4
Visible crew/equipment: When Lister wipes down the biohazard cabinet, a boom mic can be seen in the top right of the screen. Also, just before the camera moves past the pillar, the entire microphone and arm can be glimpsed. (00:05:00)
Quarantine - S5-E4
Visible crew/equipment: When the Cat tries to attack Rimmer in Quarantine, a boom mic can be seen at the top of the screen. (00:16:45)
Chosen answer: In-universe, after leaving Red Dwarf after his first appearance, Kryten managed to crash Lister's space-bike into an asteroid. Lister found his remains and decided to rebuild him, however, due to the high level of damage and Lister's questionable repair skills, he was unable to recreate Kryten exactly, leading to changes in appearance, personality and accent. In reality, the original actor wasn't available, coupled with presumably practical concerns about one-off makeup as opposed to makeup for a regular cast member, so some visual changes were made.
Tailkinker ★