That's excellent advice that many have learned the hard way... Honestly even as a non-manager it's a very bad idea. When I was a junior one of my colleagues was called to the manager's office. I assumed it would be for some mundane project scheduling or whatever, so I jokingly said "you're getting fired" as he was going there. And he was. This is one of these memories that come back to haunt you late at night when yo…
Luckily I haven't been fired since, but that "joke" stuck with me.