Hopefully she washes her hands!
OK... this was just too good to pass up. From an irc post by a co-worker

So I'm in the cafeteria waiting my turn to order.  I end up ordering a Philly Cheese Steak and the lady behind me say's "hmmm that sounds good, I'll take one without any onions!"  She then begins making small talk about how bad onions are and to make sure the cook doesn't put any onions on her sandwich.  We end up getting our sandwiches at the same time and she notices an onion on hers!!!  So what does she do??  She picks it off and throws it on my sandwich!!