I also believe there's possibility he won the mentioned amount of btc because reported the gambling site before early this year and his
withdrawal history is pretty good but he winning with the strategy he said is what I'm not quite sure or agree with cause no one can win dice game like that except the seed to the game are exposed.
1. An image proves nothing. Anyone can Photoshop nowadays.
2. Even if that image would be legit, it proves less than one Bitcoin. 150 BTC is pretty far from that.
3.
I stick to the original statement that anyone winning 150 BTC would be busy spending them and would not spend time trying to sell a method/strategy.