Dickens is shown lecturing in Cardiff on 24 December 1869. A stroke earlier in the year suspended Charles Dickens' lecturing tour until January 1870. However, the Doctor indicates that history can always change when visited by the TARDIS. This establishes the events of the episode as an alternate history.
Redpath reacts when the lid is taken off of the coffin he is in.
When Rose is locked in the room and the bodies come toward her, you can see an electric light-switch to the side of the door she's trying to get through. As the Doctor runs down the hall toward her, you can see a central heating radiator.
Dickens uses the phrase "On with the motley." This line is from Enrico Caruso's 1902 translation of "vesti la giubba", a song from the 1892 opera 'I Pagliacci'.