I don't understand how exactly the bug works. According to OP, at least from what I get it, if he bet $2.00 and lose the bet, he'll lose $1.98, but according to HousebetsIo, he played risk free, which I perceived as if he bet $2.00 and lose the bet, his balance will still be exacatly the same? Which one is it?
I think this should be clarified as it brought quite a magnitude to the case.
the bug was the gambler's account will be credited $0.02 when they lose a bet. From what I understand it doesn't matter how much the bet was, as long as the bet it is a loss, a $0.02 will be credited to the gambler's account. that's why the OP said when he bets $2 he will lose $1.98 because the $0.02 will be credited to his account because of the bug. also, according to the OP, the bug only works if you are betting using BTC.
as for the Housebet.io claiming the OP is betting "risk-free", Housebet.io claimed on their ANN thread that the OP is betting with $0.01, so when OP's bet ends up losing, his account will be credited $0.02 because of the bug.