Sounds like the trial is derailed by focus on the plaintiff's childrens' opinions.
I think that the reason he is injured, and Paltrow is not, is because she landed on him. If he crash landed onto her, she would have injuries and she would be suing.
As for his TBI, that is so difficult to demonstrate. His age works against him. Was his extensive travel after the ski collision? Was he ziplining before or after the accident? If after, TBI is more difficult to believe.
As for his opinion that he was unconscious, I'm fairly certain that people who are momentarily unconscious are not aware of being unconscious. Being stunned or disoriented does not mean unconscious.