I think the bet amount is not the most important thing he want to share, but he want to say that winning streak on 2x payout is possible.
Bet amount is the important thing in gambling. There was a guy who won 100 btc just in a bet, do you think it's not important compared this "14 winnings streak"? Or do you prefer win 14 in a row with small amount than win 100 btc in a bet?
Depends on how long can he recover from the loss. Most people do not put too much in a bet because they know this is gambling, there is also house edge too. From the start you are already at disadvantage, so try to bet all in in order to double tour balance is sure risky thing. Only some of them dare to bet that huge amount and that is only big whale or early adopter