WARNING! THERE MAY BE UNMARKED SPOILERS!
The video game Antichamber is the story of another Time Lord in a similar situation as this episode.
You never see your Tardis from the outside. Geometry seems downright wonky. The final scene is a white background with wreckage floating around, just like in the center of the Tardis. Tricky and his Dad were victims of a malicious plot by the other two brothers.
Tricky seems to imply that it wasn't an accident that left him amnesiac and crippled. It's possible that his two jealous brothers, upset that their father was going to make him Captain instead of either of them, arranged an industrial mishap to remove both father and favored son.