You have 5 minutes to roll on loot, once it has dropped. If you are the only person who has yet to roll (Need/Greed/Pass) then it will drop to you automatically, after those 5 minutes. This is the same system that is in place now.
This was adjusted later in LotA and ST (back when they still had lockouts). In those instances following the adjustment, if you didn't roll, it was considered a "pass" and you wouldn't get the item. This was adjusted specifically for those instances in response to all the people who complained about having items inadvertently fall to them.