The cop angle is interesting. They can lie but since they can't break laws like that it wouldn't be viable to potentially spread covid to try and catch smokers.
I wonder what that means for cops trying to entrap johns in prostitution cases. I've never been a john, or a prostitute but weirdly enough I have been solicited by both (I'm a guy).
You can tell in most cases whether it's cops or not. I don't think they'd bother doing that.

Your friend could be asymptomatic so you're risking death even if they have no symptoms. It's your risk to take, but if you end up barely able to breath you'll certainly regret it. I haven't followed every precaution either and my work environment leaves a lot to be desired.