I'm currently a lot lvl 26 running normal mode act 3 and 4 and i noticed if you can do high enough dmg (mine is about 900) you can 1 shot elites with cluster arrow if they are next to each other and if you kill all 3 at once you get triple loot similar to the monk exploding palm exploit. if however you only hit 2 of them and one is still alive you will only get normal loot.
I don't know if this is doable in inferno unless you have insane dmg like athene but i will update how it works in all difficulties as i level through them.
Also getting the loot to do this at my level is very easy i just bought gear from the vendors or found it on elites and put green sockets in all cept the wep is red.
ps sorry if this is a double post i posted it earlier then went back to view my post and it doesn't show up so i thought i would re type it again.