Make him mistrustful, maybe even have him draw the knife for protection, but not outright attack the pc.
He only drew his dagger some distance away from me when I fell for his ruse and saw the boar in the bush. However, when I did the smart thing and ignored him, he somehow managed to close the distance and grapple me to the ground...
The choice & consequence in this case should clearly be reversed, picking the smarter option should result with you in a less precarious situation.
