Brain injury is a huge thing in terms of its effect, the timing of those effects, and the feelings and/or knowledge. These are things that are causing those who are experts in treatment to reassess how it is and the timing.
I feel very sorry reading the thread and about the man dying. A fairly serious couple of factors are (a) extent of brain injury which can reduce to almost zero brain actions for weeks, and (b) actual competent of medical in understanding the issues. Of distress in what I read in the opening post was the brain function was 100%.