I think you're reading too much into small details.
It could very well be that McGonagall doesn't like phoenix travel, or (more likely) that Dumbledore focused on bringing Harry and Hermione into the safety of Hogwarts as quickly as possible, while McGonagall has lower risk and is also able to defend herself.
Fawkes can only transport three people at a time
Somehow that also seems unlikely to me. Phoenixes are displayed as very powerful, both in MoR and canon. Their actions are more limited by their narrow goals and maybe limits of their intelligence than by limits of their magic.
I think you're not reading enough into small details.
I'm not saying that your ideas are not possible. I'm saying, what would be the point of it? Wouldn't it have been easier just to write: "Harry caught fire and went out and blazed up somewhere else; and just like that he, McGonagall, and the Headmaster, and the unconscious form of Hermione Granger held in the Headmaster’s arms, were occupying another place; with Fawkes above them all." ?
I think it would have been easier. So why wouldn't he have written that, if it won't be relevant?
The next discussion thread is here.
This is a new thread to discuss Eliezer Yudkowsky’s Harry Potter and the Methods of Rationality and anything related to it. This thread is intended for discussing chapter 85. The previous thread has long passed 500 comments. Comment in the 15th thread until you read chapter 85.
There is now a site dedicated to the story at hpmor.com, which is now the place to go to find the authors notes and all sorts of other goodies. AdeleneDawner has kept an archive of Author’s Notes. (This goes up to the notes for chapter 76, and is now not updating. The authors notes from chapter 77 onwards are on hpmor.com.)
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