It's the easiest thing in the world for people to throw out accusations that guys are rats. And once out there, its the hardest fucking thing to refute or defend against. There's always that lingering bullshit that hangs over a guys head.
Now I'm NOT saying not to 'out' a guy, if in fact he is a rat. But you'd better be damn sure of what you're talking about. Because that kind of reckless talk has gotten many guys killed for no reason.