In this case, it would be the arbitration date. They filed before the SOL expired and were awarded judgement. That judgement may be renewable each year for a specific duration or may be good for a one-time period of one to several years.
Either way, he owes and it's most likely not going to go away. Also, with the passing of time, it's going to become even more expensive (court cost, filing and attorney fees, interest, etc.) each time the summons him to court.
He might want to run this by an attorney in your state and see what, if any, options he may have.

