The whole TV movie must be now -at last- consigned to non-canon since it says that the Doctor is half-human and this just isn't consistent with Journey's End (an apologist might say that the Dr Paul was lying). Or maybe it was all just a dream. Again.
Another explanation bandied around is that both the Doctor and the Master were mistaken in the TV movie. The Doctor because he was still addled by post-regeneration stress and the Master was tricked by the TARDIS. Journey’s End also maintained that atoms are held together by electrical forces and that dragging a planet causes window frames to rattle on said planet, so can’t be taken too literally. If Journey’s end is to be taken seriously, full timelord = two hearts. Half-timelord = one heart. We know that Dr Paul has two hearts, so he must be a full timelord. He’s therefore just confused; after all, he couldn’t remember who he was at one point.
The regeneration cheat was so annoying. Screws up everything we know about regeneration. I think they could have improved the episode by having a few more companions in there. Perhaps Turlough and Benton. Then they could have had the Doctor do nothing except smile and watch as his companions wipe out a full Dalek empire.
I reckon RTD was one afternoon watching the 5 Doctors and musing on how tough it must be to write an episode with so many characters and so much continuity and then read a Marvel crossover comic with a million other titles tied into the main story and thought ‘wow, that is really tough to get right’ and was inspired to make the biggest mess since The Sound of Drums. Had Peter Cushing and Roy Castle been alive I’m sure they could have made an appearance. The Doctor could even have given Roy a sonic screwdriver.
I'm surprised that he didn't reveal that Donna's grandfather used to be a police officer called Tom Campbell but his memory got erased or something.
I suppose that as far as the regeneration cheat is concerned, it isn't really much worse than any of the cliff-hanger get outs ("They just cheated us! This isn't fair!" screamed Kathy Bates), the worst of which was the one at the beginning of Age of Steel, and there are plenty of equally bad ones in the original series.