The point with leader is kinda missed imo, because why should he decide? He is ML and he is obligated to stick to rules. Rules are clear, ninja looting is when You are needing on item thats not useful for You (in simple words), so once again, if it is an upgrade, why this pala cant roll for it?
I would be very careful with giving raid leader power to decide about which items are bigger-upgrade for particular classes, cause it makes a really nice spot for some disturbing. Obviously, spell power back is not for war rogue etc, but when it will come to situation when RL will decide if dropped item will be better for Player A or Player B and will choose who can roll, oh god, so many possibilities for some cheap tricks.