You have it wrong. The only loot that is assigned is tiered gear. This included Tionese, Columi, and Rakata. The only loot I've seen so far that is not auto assigned is schematics and dropped crafting mats.
If you're playing HM or NM, master looter works as intended (besides bugging out sometimes, so you have to give the players who get items leader+ml so they can take their items for themselves). It's only in normal mode that items get assigned, most likely to prevent ninjaing items when PUGing operations. Since Rakata starts dropping in HM, it shouldn't get assigned randomly to a player in any case (or other stuff for that matter) - only if you forgot to set the loot mode.
My question is how do people in HM's and NM's decide who gets the loot if 2 people tie for it depending on what kind of loot system you use since you can't /roll, do you duel to the death for it?
Easy answer: Loot council.
Obviously doesn't work if you play with a GM and/or officers who are total *****s or people who can't stand the thought of getting no chance at an item in this particular raid week.
Or Need vs. Greed which means rolling for it, naturally doesn't work well with derps who roll on wrong items or on items that aren't an upgrade for them.