Don't worry about it!

I've had the same thing happen to me after my non-ccg friends have followed me to various boss runs. If they end up without me, I try whispering to them things like "No problem", "Stay", "That's the way to do it", "Right on" and "Yes" (when they do stay). I jump with the smiley face so they can see I am happy for them. If they jump off I say "No".
Another thing that helps is to make them wait until the exact time the run starts so you miss the first wave of toons pushing in. I make my non-ccg friends wait in the pit for the run to start by saying "Let's wait for my friend". Then they can see that all of us are together when we all run to the door together. When jb's start flying, it dazzles them enough they don't mind the wait, LOL!!!
A couple of my very good non-ccg friends have discovered they do really good on the boss runs when they go with me and are finally listening to me when I tell them to stay (I am very persistant when I tell them, lol). I have left them behind before after staying on the elevator during a shuffle they jumped off of. I say "Sorry I can't" and "Don't wait for me" hoping they understand I can't jump off and they are to go on the next elevator. (they usually do). Many of my friends who follow me are still cold callers (I am a mingler thanks to the ccg!), so I keep hoping they can see I am on to a good thing and not out to ditch them.
We can't do anything about randoms, so don't worry about it when they shuffle. I think we are getting really good at packing the elevator when they happen (most of the time, anyway). Keep working with your non-ccg friends by repeating appropriate speedchat phrases and hopefully they will realize what you are trying to say to them.