Hamish Wilson who play's Doctor J.M Hiller appeared in the official Doctor Who serial The Mind Robber in 1968 alongside Patrick Troughton. Dr Who regular Frazer Hines who played the Doctor's companion Jamie McCrimmon came down with chicken pox and Hamish was brought in as a replacement actor until Hines recovered.
Tragically half way through filming Bill Murdoch died suddenly and was replaced by Robert Radcliffe The team decided to tweak the script slightly so that Murdoch's scenes could be kept as a final mark of respect to the late actor.
The initials 'J.M' in Doctor Hiller's name badge are an abbreviation of 'Jamie McCrimmon' as a tribute to 'Hamish Wilson' time on the official Doctor Who series.
The unknown Doctor that appears between Paul McGann and Christopher Eccleston on the Torchwood Dossier is Dr Who fan film actor Kenneth Raymond Moore from the fan film Fire and Ice. This was placed as a nod to this film and their initial plot twist that revealed his Doctor was the forgotten Doctor in the time war, this was created approximately 5 years before the creation of the 'John Hurt' character that is introduced at the end of 'The Name of The Doctor' in Series 7 of Doctor Who.
Greg Hemphill was cast as Commander Cooper but pulled out due to scheduling conflicts before filming began.