The sooner you start smacking people with tribal knowledge, the sooner many people start to back away slowly.
I used to interview ex-coworkers. I don't do it as much anymore because it gets old/depressing and the answers tend not to change that much.
If, for the purposes of thinking about turnover, you look at a former colleague as an 'aggrieved party', we are generally somewhere in the neighborhood of mediocre at agreeing that certain things were the 'final straw', and work backward through that to actions to increase retention.
One of the things that interested me about these conversations was that people tend to work chronologically backward through many of their complaints. But what was surprising was that some people would go all the way back to their first weeks. To the first straws. The warning signs they ignored. In a way this is not unlike talking to someone who just broke up with a romantic partner.
And while their ex may realize that his/her problems started back with some early inconsiderate behavior that snowballed, and resolve to 'do better next time', I rarely see companies do this, unless I instigate it.
Point is, these petty slights stack up, and can become a big part of someone's narrative for abandoning you (often in a huff). First impressions are important, and you dismiss them at your own peril.