Oh no, I hope that wasn't too hard on them! In Sodalitas we have Stress instead of hit points, which makes it easier to make up what happens to the adventurers — some think characters should only die when it's their player choice.
Nah, it was only a knock out and the rules are very genorous: every character is equipped with two health potions, which can also be used on other character. So if the fight would have lasted longer his sister could have revoked him.
But as a modern girl she was reaching for the boss killing fame for herself. And killed him indeed.