It's still a double elimination... After you lose twice, you can't finish in 1st place. Onizuka could have made 2 equals 7th places, but went for a 7th and 8th (which I think is good). And even if you are out of the tourney, you need one more match to decide if you can avoid the shame of being in last place and same goes for 5 and 6. Ranks number 2-3-4 will be the only out each time, so no need for a seeding match.