In dice where your luck is decided in milliseconds by one roll, mostly by server seeds, I think it's really hard to bet high amounts of bitcoin so easily and 50 bitcoin is really high amount, he is very brave to risk that much and I'm glad luckily he won.
Btw if anyone knows, that's the max bet and wins on stake? I couldn't find FAQ page there and it wasn't written on elsewhere (and are max bet/wins the same on stake and on primedice or this last one offers higher limits because of being dedicated to dice?).