First of all, Erica didn't write the unlock application itself. The iPhone Dev Team did that, and it apparently is a real, no-code-stolen software unlock-- put it on your iPhone, run it, and then use any SIM you want. Erica only started to write the barebones of a GUI application for the unlock, and gave that code to the dev team.
Which is where this haRRo person gets involved. He, a Belfast, UK man, is not a member of the dev team, but pretended to be. He apparently took Erica's code out of the IRC channel, with the intent of selling it as his own application. He even got an offer from an Australian company, $50k AUD, to allow the application he said he'd written.
But he didn't write it. At all. Because while yes, the code he tried to sell was updated from Erica's code, it wasn't by haRRo. He actually contacted another coder to do the job-- who we spoke with, and our IM conversation can be seen after the jump.
Update: Post updated below.