What is your HR climate?

I understand the necessity of an HR department. Really, I do.
What I don;t understand is the need for what I consider to be petty crap.
Yesterday I sent an IM to someone by mistake. It just said “kill me” in context with some stuff that was going on. Nothing major, it was in keeping with some jokes going back and forth. I saw my mistake and sent the person another message; Sorry, wrong person” and forgot about it.
Today I came in and my boss, who was the personI meant to send the message to, asked me about it. Apparently the person forwarded it to his boss, who forwarded it to the HR HEAD! HR messaged my boss who said thank you and deleted the entire thing. He wasn’t angry, just letting me know about it.
He also told me that basically, some people in certain departments are known for being “tattle taley” types.
The wholle thing to me was a tempest in a teapot and the response was ridiculously disproportionate. It would NOT surprise me for a HUGE unvestigation to take place, though my boss assures me that I’ve heard the end of this.
I certainly hope so. Lesson learned when sending messages.
I still feel like it was stupid.
What is the climate like where you work?