Derman is like many older white male American docs I've met, worked with, been treated by, taught, etc. VERY intelligent, HUGE unchecked egos, and once they get their MD degrees think it automatically qualifies them as experts to do anything and EVERYTHING they feel like doing - without ANY additional training - from being university presidents, to lawyers, to piloting jet planes, and on and on and on. They REALLY do. It's amazing. Their hubris knows no bounds. They are "legends in their own minds."
IMHO, when this guy came to court he was just SALIVATING to become an expert witness, not just in this case but here-after. It would be another "feather in his cap" and would add to yet another page of his 110-page CV. He just waltzed in there believing that he knew EXACTLY what the court needed to hear and HE was the guy who was going to tell them - to set them all straight.
I can't stand this guy.