It's implied. It's one of those things where you'll see people talking to each other around the water cooler, you'll come up to them and ask what's going on, and they'll just casually make up something like how they're talking about the weather. You know they weren't because you caught snippets of the conversation, but for whatever reason, they aren't going to fill you in on what it was really about. It's a casual kind of mistrust, like you'd have for a coworker who is prone to being the boss's favorite while you and the others are talking shit about management.