This is not tested only though of, my reasoning for that this will work is that if you pull a large amount of mobs in lets say in stockades with thorns on and you do not damage them then if they die by thorns they will die and you will not be able to loot them because technically you did not damage them.
My theory is that if get a druid to get alot of mobs down to like 5% with thorns and then drop group the toon that AoE'd them down will get full experiece for each kill.