I think you should see everything wrong with that. For someone who admonishes people to gamble or trade small amounts they can afford to lose, you should. I take your last sentence for it. He definitely made a wrong move, and will forever regret it. That's if he doesn't fall into depression from that loss. No matter how rich that dude wants to act he's, that amount used is too huge to toy with. It will shake him out of his stupidity.
Let us assume he used 20x, that means he used $5 million to trade.
The reason I said so is because if he used just 1x leverage, his losses will still be better and he can not be liquidated even if bitcoin get to $1000 from $100000, although not good. We may have different opinions about this but leverage is the reason he lost all the money. When he got liquidated, he would have only lost not less than $250000. And he can easily see the money back if he is patient.
Did you know he opened long position with $5 million recently after the loss?