We had a gal in our shop order a Taser. When she came to pick it up we were all looking it over (as none of us had ever seen a Taser-brand taser before and we wanted to see what it was all about) and she asked a coworker if she zapped someone and he was touching her would she get zapped as well.
My coworker said no that it just didn't work that way.
Now, I'm not necessarily up on my science and current vs volts and all that, but I do know that we humans are pretty good conductors and one of the reasons you push someone out of the way with a non-conductive material if you think they are getting electrocuted is so you don't end up getting fried like they are.
Wouldn't the same thing apply to Tasers and stun guns?