Usually losses by the odds of 1.01 is comparatively less. But it's nothing but bad luck and he had to lose from that particular bet.
I wouldn't blame everything on bad luck. If you never bet and decide to make a one-time only bet with 99% chance of winning, then you can call this bad luck. But I'll be guessing that unfortunate guy made similar low-payout-high-chance bets in the past, felt invincible, and pushed it a bit too far. If you keep risking money like that over and over again, the loss is inevitable.