I see what you mean and to be honest, the rules might be explained in more detail if my theory is right.
A winning streak can't be lower than 1.50, but can be as high as you want.
A losing streak can't be higher than 4.00, but can be a low as you want.
By winning that one bet, you discontinued your losing streak and started your winning streak, which was then broken by the next lost bet.
I get your theory, but it is not spelled out that way in the rules, which explicitly state that bets outside of the criteria
do not count either way regardless of being a winner/loser.
I am still waiting for this to be addressed. It also looks like there was a valid streak before mine - and another one after mine. Very concerned that BetBTC hasn't been around to give us any sort of answers. Not a good sign.