Accepting arguendo that this means he hired some lesser qualified people, is there any evidence AT ALL that it was one of those people that are responsible for

Accepting arguendo that this means he hired some lesser qualified people, is there any evidence AT ALL that it was one of those people that are responsible for this? All the video I've seen of this guy makes him seem almost suicidally indifferent to safety. There's nothing any of his subordinates could have done except warn and quit and it's my understanding they did just that.