It sounds like they need to have a set amount of time where the person cannot attack or be attacked when they logon. Maybe a counter where if they do it too much, it adds minutes to their hold time.

wasted adrenaline shot on friend, about a case of water and tons of food. Never came back from unconscious state.

same was trying to revive my friend, we both logged out to get to another server near each other and I lost my character.