In the Episode 'The Crime Machine', Holmes freaked out when Watson got shot in the leg. In the Canon story, "The Three Garridebs", Watson was shot in the leg and Holmes freaked out there. So, it was really a case of deja'vu for him.
The reference to Moriarty being a Star Trek fan makes a lot more sense when one remembers in the original canon, he was an astrophysicist.
Fridge Horror: As pointed out in his profile, the proportion of Tennyson's chair to the rest of his body and the fact that we never see him out of it could very well indicate he doesn't have legs. What in the world caused that?