There's nothing wrong with using an LB on a massive trash pull if it was unused during the boss and there's time to refill before the next boss. If it blew the group's chance for an LB2 for final boss that's less desirable, but I certainly don't think it's behavior worthy of a kick. At most, a couple words from another party member saying why that wasn't the best use of LB, then move on and clear the dungeon. -_-