Lost under $ 10 000 why not try lodging a "Minor case Claim"...

Lost under $ 10 000 why not try lodging a "Minor case Claim" against Gary personally at your local court?
You will have to front court yourself as will the great Gary, as lawyers are not permitted to represent clients. Costs virtually nothing, just your time.
If he doesn't turn up to pre trial hearing you will be awarded the case.
If you win he will have it recorded against personal credit rating, and can only have it removed if awarded sum is paid and you give your permission.

Would be a real pain to Gary if there were 200 of these lodged against him.

Not legal advise but a suggestion that someone may wish to look into.