When Sarah is trapped in the cylinder, the metallic bands around the cylinder are just grey gaffer tape (as seen by the wrinkles in between the two buttons).
Near the end of the episode, Sutekh says that he can move again and stands up, and there is someone's hand on the seat of his chair which then moves down and out of sight.
The Doctor mentions that radio waves take two minutes to travel between Mars and Earth. In fact the delay varies between 3 and 22 minutes, depending on the two planets' orbital positions.
Sarah states that the puzzle in the pyramid reminds her of the city of the Exilons, referring to the story Death to the Daleks. However, Sarah never went into the city.
In the final scene, as the Priory catches fire, the Doctor tells Sarah they should leave as they don't want to be blamed for starting the fire as he had enough of that in 1666. He is referring to the real life event the Great Fire of London. This foreshadows the Fifth Doctor's adventure in "The Visitation" (1982) which resulted in the Great Fire Of London, but the Doctor had not yet lived through that adventure and so could not have any knowledge of it.