This isn't official, but on one of the early threads someone who IMO seemed quite credible, claimed they were close friends with people in Allison's circle and posted a few things about their situation, and one of them was that Allison and GBC were having counselling, and that part of the work they had to do as a couple was that they had to have a discussion every night. Possibly as a way to ensure they were communicating and staying in touch, and also sorting out issues promptly rather than letting them fester. Sounds feasible. If this is the case another reason for a raging argument could simply have been that Allison wanted to have the discussion and there were plenty of 'issues' to talk about, and GBC wanted to avoid the discussion altogether.
I have experienced something similar in 2 past relationships and in both cases my partners at the time would do almost anything not to discuss issues, and would go into rages if you tried to bring anything up. There was never a good time, there was never a nice or tactful or positive way to discuss things that would make them any more amenable. They simply did not want to hear about any problems that involved them having to change or do anything, just the very mention could cause a frightening reaction. This of course is not sustainable, there is only so long you can go sweeping things under the carpet and expecting your partner to say nothing.