WS
About Colgan - a few years ago R Zumwalt, NTSB Chair at the time, gave a guest lecture that I happened to attend. He commented on the subject of how pilot fatigue had been treated as a possible contributing factor in the Board's report.
The way the subject was raised, someone asked about whether an accident would need to happen for regulations to be tightened with regard to crew rest or fatigue.... the Chairman's reply: "We've already had that accident." It was quite a stark reply.
(The question was not mine. I asked something about the Air Canada 759 taxiway line-up incident at SFO in summer of 2017 - wish I could recall more specifically.)