Irony much?
You're assuming the opposite, which is why your argument sucks.
On topic, being proactive, HAD you known this character doesn't mean you'd run off behind his back to tell the world his details.
If indeed that you were close enough to know or find out the truth, asking him directly what the story is, then asserting weather or not to A) Notify him of this thread/stories etc and counter it/save rep/ or -
B)If you aren't happy with what your "mate" has done to make a quick buck, this is where the integrity bit comes into play, you'd notify the OP and help as best you can.