When Poul (David Collings) is talking with the Doctor and Leela (Louise Jameson) in the robot repair room, where the Doctor and Leela have been restrained, Leela is wearing earrings.
Crew member visible in the mirror after Zilda enters her quarters.
The Doctor, who should know better, uses the oft-repeated logical fallacy that the bumblebee cannot fly. The original fallacy came from the assumption that a bumblebee's wings are rigid; they are not.