I would definitely not call this "fair", because this is supposed to be gambling, and gambling doesn't involve calculated bets in that fashion, even though almost everyone tries to "beat the house".

You figured out a way to do that, and truth is, that most hackers or "geniuses" in real life would get paid to help preventing these type of things going forward.

Looks to me that you knew that this would work, and instead of telling them about it (so they could fix it), you used it for your own benefit, and probably would have continued to use it if no one found out about it...

Personally, I would have done things differently, but I guess it comes down to the individuals ethics and morals.

That being said, I'm still glad that this stuff happened even though I don't personally like how it happened, as I truly believe that gambling dApps can have a great impact on Steem in general.