AJ explained it perfectly. Highest seeds of players who lose, are put into a pool, 5 players (at least). Basically a "pick out of the hat" type thing, in this case at least 4 guys will be selected since there are four LL positions.
I remember the year where there were around 6 LL's and Horna lost in the last round to Junqueira, he was seeded #3 didn't get in. Then someone pulled out and he was in, funny enough the draw he got was better.