Man, there sure is a lot of speculation in your post, Kid.
In my humble opinion, once a guy airs you out and then doesn't meet his promised make good date, it's up to the guy who got barrelled how he wishes to handle it.
I suppose if the guy was a good gambling opponent for many years and always made good before, there could be something going on in his life currently thast made him do this but that doesn't excuse stiffing someone - it's just a possible reason why.
If the op of this thread wanted to be gracious and forgiving or alternately pissed off and not forgiving, that's all up to him.
The other dynamic that comes into play is how the gambling has been going between them. The op hasn't said, so we really don't know whether they've been playing close and splitting winnings or if it's been lopsided.
My guess would be that if it was lopsided to the op's favor, this thread blasting the other guy probably wouldn't have been put up.
That's also speculative.
best,
brian kc <--- wishes he had a quarter for every time he heard "I shoulda made him post"