I've looked over the TOS several times, and it really looks as though we're (referral people) are ok:
Game pieces and Codes thereon will be void if they fail to pass anti-fraud detection measures, or if determined by Sponsor and its agents in their sole discretion to be any of the following: duplicated, photocopied, reproduced, forged, defaced, tampered with, mutilated, cut, torn, erased or blank in whole or in part, illegible in whole or in part, smudged, disassembled or altered from the form in which it was issued (i.e., cap liner removed or missing on a bottle cap game piece), stolen, transferred, bartered, traded or auctioned (including, but not limited to an online Internet auction site), unissued, unauthorized, illegitimately obtained (i.e., through means other than retail purchase or free entry request), or if they fail to contain special markings, inks and/or security codes that may be applied by Sponsor at the time of production, or if they contain an unauthorized message, code or other marking not issued by Sponsor for use in this Promotion, or if defective or if they contain printing or other mechanical errors or are printed or produced in error.
I mean, shit. I obtained my codes legitimately, and they were all free code requests.