When Eight regenerated into Nine possibly explained

So, here's my theory, based on things Brown Suit Doctor said about Blue Suit Doctor, and the ways he compared him to his Ninth incarnation:

The original Doctor explains to his other self that he was "born in battle - full of blood and anger and revenge," then looks to Rose and explains that, "That's me. When we first met."

This makes me think that it means that the event that caused Eight to die and regenerate into Nine was during the Time War, either before he did what he had to do to end it, or as a result of whatever he did to burn up both the Daleks and Gallifrey. That would explain why he said that the person he was when he and Rose first met (ie, Nine at the beginning of his incarnation. If you remember he hadn't even seen himself in a mirror yet before he entered Rose's flat) was like the new Doctor.

Well, it made sense in my head.