I think it might be a legal/ethical thing too. I could see how if something like this happened with a certain t and a certain patient, it could be blown way out of proportion and end up in a legal battle. Maybe you need to make contact first. But what the hell do I know? I don't know about the boundary theory...I actually don't know much about boundaries at all...sorry!
I am always paranoid that I might see my t at my work!! Vancouver has a pretty small downtown area and shopping strip and I work right on THE shopping strip in a REALLY popular store and he lives in the neighborhood!

So far it hasn't happened but I bet one day it will...