Most of his profits come from the long losing streaks. If he was base betting at 2.821x (from picture posted) and almost doubling his bet size, then after every loss, the next win would get him a big profit. So a win at 1 BTC bet, would give him a profit of around 0.6-0.8 BTC. If he loses that, then the next win at around 2 BTC would give him a profit of around 1.7ish BTC. I guess his bets , when he was at 12 BTC profit, had these long streaks, and that is what got him back. But only 2 more losses, were all that was needed, for his next bet to be 6 BTC and 12 BTC.
So unless, he takes those risks again, and get lucky. He will still continue to lose more.
Also, maybe, he should have stopped at 33 BTC and probably started with a new account
, so as to atleast sell this strategy and make some profit out of people, who would have blindly believed in him.