My two cents worth:
(And yes, I can still use pennies at least for a little while yet :P)
My first question is, do you have a Private Investigators license for your province? If not, you may have broken several laws without knowing about it. If you do, I assume you followed all proper procedures.
The code of honor between hobbyists only extends as far as we ourselves are willing to make ourselves adhere to it. I would never 'out' another hobbyist or SP, but I cannot expect every other hobbyist to do the same. (I do expect an SP to be discreet, unless she gives some indication otherwise) You have to ask yourself if the 'Code' of the hobbyist in you supersedes your ethics as a Private Investigator.