for someone is if in the exit interview (not layoffs, the ones that leave voluntarily), the person owns up to things that went wrong because of what they did and that it's not just a "here is everyone else's fault" fest. Unfortunately it's a slim minority that do so. And most people think they are "their own worst critic". The reality is that's a complete lie.

If I ever consider boomerangs I look at those people who had some introspection first. Rarely take back those who just threw everyone else under the bus.