The chain really goes back a lot further than that. When you look at the history of both those pilots, my opinion is the chain started with their instructors who signed them off for their private checkrides, and arguably the DPEs who eventually passed them. Now, that may be a bit harsh - they could have potentially been fine in piston singles, but when you read the full NTSB report with the histories of both pilots, they failed multiple checkrides at multiple levels. The system is supposed to stop people who are genuinely bad pilots from getting into the seat of a Lear or similar high performing aircraft. Unfortunately, the realities of the system are that those people are given too many chances. Most wash out, but some make it through the cracks. I can think of another person who doesn't participate here anymore (at least who I haven't seen participate in a while) who I expect to have a very similar NTSB report one day.