Yeah, that 0.5 roll was a bit risky one, with high odds as well, dude managed to get 8 bitcoin versus 6.5 lost but that is just one picture, we do not know what happened before or after that. I am afraid its quite risky to win like that, it would have to be pretty lucky to end up in a good margin of profit, usually you end up losing a ton before you recover in those bets, like for example losing 10 times in a row but then winning like 3-4 times in 7 tries and suddenly you are closer to break even.
I have been around crypto gambling for about 7 years now so I have done all the things you could think of as strategy and I can tell you that this one is a pretty brave one, I wouldn't dare to do it. Not that it has any less chance to win or lose, they are all destined to house edge, but this one can end up losing too quickly.
Judging from my investments over the last week,,, he probably lost more later on (investments went down and then back up in profit for me). OR it was completely unrelated:)
But anyway, everything is risky, putting all your bankroll in one bet or many few bets, to win the same amount? It's all relative to time, but eventually has all the same probability. And amounts are relative to your wealth:) If all I have is 0.5 BTC then I am "brave" to go all in. But that guy probably had a lot more? He is less "brave" but anyway, kudos to anyone who gambles and has fun, that is the whole point:)