Re: lets say I had a +EV method for a dice site, how much would you pay to know it?
I have checked almost all scenarios from that table and all have the same result. And I trust my simulator more than I trust your math 
I realize you are justifiably proud of your site which looks very nice and no one likes to be threatened with "I have an exploit give me coins" of which I'm sure you get many. However, if dooglus says there is a problem, there is a problem.
Is it possible that dooglus was doing something with his bets, or seed, or other doogmagicTM that you are not putting into your simulation?
After all, you didn't detect the rounding bug until it was pointed out. Fortunately, the % bets needed to be made were such low probability that it was still a high variance outcome to exploit the player's EV advantage.
You've already graciously offered a 1 BTC reward maybe stick with that as things unfold.
Regardless good luck to you and your site and kudos again to substrata for finding the rounding error.