A draft post is identical to a regular post. 
The URL is the same, plus it is a live web page, so, it's visible online.

The only thing that changes, is that a draft post does not show up on the list of blog posts.

Basically, there aren't any internal links to it, but, if you link to it externally, it will be found.

Yes, your post got shared.

Being aware can create all kinds of conundra.  Obviously, things occur when one is unaware as well.  Ah, the mystery of life and ActiveRain are once again closely related.  

I didn't realize you could share draft post. Never thought about it.

If I share a blog post, I do so via our website.  Interesting that this situation happened to you without actually publishing your post. A

I usually only share my posts from my website, not ActiveRain anymore.

I don't think you did.  Might have shared a non working link you may need to delete from places.

you can bring it back & forth from draft to post. Don't know why you'd want to share a draft but I guess OK.

Mercury is in Gatorade, after all!

Impossible is clearly possible.

Now you can revert to draft and repost! LOL

I never use the share buttons . . . now for sure I'm not. I just use the link!

I had not thought about that. Thanks for sharing your experience.

I use them to share my finished posts but never tried it on a non finished one. Good to know that it can happen though

I never use the buttons on the left, but Dario Ferreira has your answer!

Another lesson for all in the world of AR.

Hope you went back and completed any alterations needed and posted it quickly after this mistake was discovered.

Looks like you have your answer.  

I do not use the AR share buttons. 

Good information here. 

Good to know, Peter - I had no idea you could share a draft post either!