You can absolutely tell. Look at that person's recommendations and what they say. Are they well-connected to many of their past employees or bosses. If not, I'd say there might be a problem. You are an idiot. Do some detective work. Everyone on CP just bitches. Another problem I have seen is how "bad" managers get a new boss and become "good" managers. Just like with the rep, often it is the people at the top that make life miserable. You can also do a search for that person's name on CP or even Google and see what posts pop up. Guess what? You can even check them out on FB and other social networks. God, you are stupid. Honestly. You have a damn computer with internet access. Use it.