It sounds to me that this functionality needs a little polishing. It would be vastly improved if the death blow option only appeared when the person is literally at deaths door, that is, has taken a hit that would otherwise be fatal. At any other time it should allow the person yielded the opportunity to accept or make a free attack. Once the free attack has been taken the fight continues as normal, i.e. fight or flee as your yield has not been accepted. Now the accaeptance could be by clicking on accept but the free attack should also clear the popup, you should not need to click on it to then make your attack. There might be a reason this would not work. It would depend on how it got implemented.
