Spam is really when you go off topic in a thread in my opinion. You might say something like, "I like pie" in a thread about the presidential race. Unless the thread is being directed to pie, that statement should not have been said. I don't believe moderators would do that.
If a mod did indeed ever spam, it could in theory be flagged and deleted. But will it ever really happen? Nope. Because us mods are super awesome upholders and them there laws! XD