I had tried fighting this Faint-hearted Knight before…he randomly appears just outside of Rattay Mill and challenged me to a friendly duel.
The first time I tried fighting him…he totally kicked my ass! I had not even done any combat training at that point.
However, after much training and getting some actual armour…I tried again last night. And this was the result…
I knocked him unconscious with the Headcracker perk. Though I trimmed the video right after the battle. What happened was that he woke up and gave the exact same dialogue as the earlier time I had tried fighting him …he acted as though he still won the duel!!!
And he walked off without even picking up his sword!
Seems the Headcracker perk prevents the game from acknowledging your victory.