Could the "pizza guy" sue now had he not received the pizza?
No, he wouldn't be able to sue.

Basically the Statute of limitations for scam is 5 years, after this delay the claim can be dropped in court.

Even if he still went for it, he would only be entitled to the USD value of the transaction at that moment. It would be unreasonable to ask for a refund 10000x the price that was paid, see I paid in bitcoin, now I&#39;m owed a refund. Can I demand it in bitcoin too?