One of the changes in the Shores of Evendim patch is that the default Roll/Pass options for loot distribution in pickup groups has been replaced by a need before greed system. When a rare item drops fellowship members are give the choice of Need, Greed or Pass. I assume that anyone who hits need gets priority over those who hit greed.
There is much pontificating on the forums about the ethics of when you should or shouldn't select need. Personally I think it is too complicated for the average pickup group. Need before greed relies on an honour system where people are expected not to pick need on items they cannot actually use. However it only takes one player who is greedy or uninformed to break the whole system and upset everybody.
This situation is aggravated by an annoying quirk of lotro: The same right click that is the default method of initiating an attack is also the default method of looting a corpse. Oh and did I mention that the default loot roll threshold on lotro is set extremely low? Every piece of crafting material (including scraps of leather) is rolled on. The net effect is that in the heat of battle loot roll menus keep popping up in the middle of the screen as players accidentally loot corpses. I have tried and failed to move these boxes out of the middle of the screen but inevitably they obscure the action and I am forced to press something quickly to get rid of the box in order to see what is going on.
If the item is a weapon or piece of armour that I obviously cannot use I will pass (or press greed) but trying to assess in the heat of battle whether that particular shimmering dragon tooth is useful for my crafting profession is just too difficult.
It is possible that the loot rolling threshold can be adjusted to exclude crafting items but pickup groups invariably use the default setting. In the mean time the only sensible approach I can see for pickup groups is to press need on everything unless it is obvious that my character doesn't need it. If you see me get something that would really benefit your character - just ask. I will happily hand it over after the battle.