Nopes. Whatever be the max-win, miners can not cheat without risking 12.5 BTC loss at their end.
Sure, that's correct. I mispoke about max profit, it's more related to the max bet, but the logic still is sound. Block discarding (throwing away 12.5 (+ fees) btc) is often the economical choice, if the bet is big enough and you're a big enough miner. Especially so in low-payout bets.