I mean, it sucks that it happened, but it's great that she found out before it went any further. Dodged a bullet there.
One of my "ways to identify good people" is pretty simply. See how they treat service workers, or others that they don't have to treat well. If they are nice and kind to people that they don't have to be nice and kind to, that's usually a good sign.
And while I might bemoan the spread of the tipping economy to all interactions, I still think that in America, you can tell a lot about someone from how they tip at a restaurant. Not everything, but some things.