A couple of years ago, a director friend of mine called me and asked about an actor she was planning on casting in her upcoming show. I had worked with him previously and she had heard some unpleasant things about his reputation and wanted some input.
"I would advise you not casting him," I said.
"Really? Are you sure?" she replied.
I went onto explain how this actor would inevitably become a disruption in the rehearsal process because, to put it bluntly, he was an asshole.
Despite my warning, my friend cast him anyway and sure enough, a week before tech week, the actor quit the show because he didn't get along with the director.
Reputations may often be exaggerated, but many of them start out in truth. If someone in your theatre community is known for being difficult to work with or unreliable, chances are, there's a reason for that. I've never met a director who made up a story to falsely depict an actor's behavior. So if you're warned to stay away from casting a certain actor, you should heed that advice.
Also, for actors, know that directors talk to one another. If you burned bridges due to your attitude or professionalism, word can spread around fast. So keep your egos in check.
But when it comes to casting difficult performers or hiring an obnoxious crew member, if you ignore the warnings, then don't be made when we come back with an "I told you so" down the road.