We had one at CAL that was famous. He had multiple training failures, CRM problems, line flying issues, etc. He had a huge file in the chief pilot office but every time they tried to discipline him, he shouted discrimination because he was a Muslim, and the company would back down and do nothing. He finally was given the option to retire or be fired after stalling a 737 at max altitude trying to top weather that he should have gone around. He flew with mostly reserve pilots.