This is not a bug. It's quite possible that someone can be bountied 49 times and then battle another player over 500 times with a 240 survival streak. many players battle back & forth this way. It's quite possible the player kept healing after being bountied by another player or players & when it was over they continued playing the game with another player or players. Or weaker players were trying to battle this player giving them a point against the survival streak. There are many variables to this situation.