Is it intended that once a fox knocks someone out, they should hang around until the player character recover consciousness, then reinitiate combat? It appears to be a hopeless situation for the victim, without outside rescue, since they don't recover enough to have a chance of getting away. (Being out of stamina prevents running, fighting back, etc.) Fortunately it's slow, so there's a good chance of rescue.
Whether or not it's intended, it's at best an unannounced change; I believe that this didn't happen in the old days when level III foxes were hazardous to me, pre-path-finding.