very unlikely that 99-QQ would make such a small bet on this flop. If they are playing for overpair status, this is a dream flop for them. With the flushdraw and the low flop, I would expect all overpairs to make a big bet at this flop, as KK did. Although, I would probably raise more, and then fold (except that I would know I should fold, but in the heat of it I would probably call).