Moltov fire damage only from NPCs?

If I have zombiehorde NPCs throw a moltov, I want it to do damage to bases and players, but block moltovs being thrown by players from doing base & player damage.  Is there any way to tweak the rules and/or config to make that a possibility?

hi, molotov's can be thrown by players too so that wouldn't work with a rule.

zombie horde has options for this already I think.