It's quite possible to make bad decisions that turn out well and good decisions that turn out badly.
To learn the correct lessons, he needs to work out if his original plan was sensible given what he knew (or could reasonably find out) at the time and he's just unlucky, or if the decision to invest was reckless or based on inadequate or wrong information.
Having said that, it's so easy to deceive ourselves, that I've heard people say that it's a good idea to work out what would falsify your assumptions before investing.
The decision he made was either a good one or a bad one based on the information available to him at the time. That will be true regardless of whether he becomes a billionaire in the next month or goes entirely broke.
The true lesson to be learned is not dependent on the outcome.
But that wager makes no sense at all since people accidentally delete there wallets all the time and there's a limited supply of bit-coins.
If you factor in time bit-coin can only go up as long as people are still using it and i have confidence bit-coin will reach wide adoption.
I hope it doesn't end up so, luckily I'm not in a position where I need to try and work it out!