The bug was that for a certain number of rounds, the user would get paid out their auto-cashout multiplier regardless of whether it was higher than SpinBPS.
I see it now. The spreadsheet was hard to read because the line with the labels was not frozen at the top.
It should be fairly clear there was a bug, provided the information from FJ can be believed.
I agree that most casinos do not normally payout winnings when a machine is not working properly, however casinos can choose to do so. My concern about the OP's case is FJ did something very similar to giving the OP chips, which is the same as paying out -- the OP subsequently used those chips to bet on another game and won.
I would also point out, according to FJ, over 15 hours elapsed from when the OP stopped using the bugged game to when he won the jackpot on plinko. I believe if FJ intended to not honor subsequent bets from funds won from the new game, they should have frozen his account as soon as they were aware of the bug, which should have been far before 15 hours later IMO.
According to my calculations, while playing plinko, he was down at most, 004096 BTC, and his subsequent bet was 0.0256 BTC, resulting in a total required bankroll of 0.06556 BTC to place the subsequent bet after his low point. During the majority of the OP's plinko betting session, he was making very small bets, and he was down by this much less than an hour prior to his jackpot win, and he was previously down nominal amounts two hours prior to his jackpot win.
The OP initially deposited ~0.009 BTC, and if you assume the subsequent bet would result in the OP having a zero balance, he would need to make bets approximately 13.727% of his actual plinko bets, resulting in a payout of approximately 2.745 BTC from the jackpot.
The OP was however due a bug bounty of 0.08 BTC (he actually received 0.2 BTC, but the advertised amount was 0.08). It is unclear when this would be payable to the OP, but I don't think it would be unreasonable to say he should have received it within 12 hours of finishing play on the bugged game. If the winnings from the bugged game were removed, and the bug bounty was added to the OP's account, he would have sufficient funds to cover the bet that resulted in his jackpot win, and as such, I believe there is a strong argument he should receive the entire jackpot win.
Separately, I am concerned about how their
bug bounty thread reads. Specifically, it says "...find bugs in two new games just released...", which implies they did not invest resources required to release a working game. There is also the implication that FJ may have been trying to "freeroll" their customers by displaying large wins -- if for example, someone deposited 0.1 BTC, thought they won 2 BTC, and subsequently lost 0.102 BTC (after increasing their bet size) on another game might have their entire deposit seized, but this player might not have made as large of bets had they not thought they were up 1.9 BTC.