Very bad judgment professionally and personally. Given to dropping bricks (an old-fashioned British expression meaning to unintentionally insult someone), so impulsive he once got fired for shooting his mouth off at the director Peter Hall and overindulging in booze in front of producers, directors while embarrassing his entire family. Sort of proved to me that Mensa was, as Christopher Hitchens wrote, a crock.
Having a high IQ doesn’t mean a person can’t make bad mistakes and be a total s**t. There are plenty of high IQ people who are disasters as human beings.