'I was at GenCon' hardly seems like enough evidence to support that amount of rampant speculation and attacks, not to mention the false claim that nobody received the free PDF for their GenCon purchases when plenty of people did.
Anyway, that aside: The actual problem is quite simple: The Shadowrun subreddit decided to ignore their rule 4 (Don't Pirate), so one of their moderators posted the free download code on the very day the PDF went live in the stores. As such, a single code has been proven not to work so CGL needs a better approach, which might be why you didn't receive a code at PAX.
But already before the PDF came out in the stores, did people successfully contact CGL on Facebook about not having received a PDF code at GenCon. So I think doing the same about your PAX purchase is a good option, Parceval, and I wish you good luck.