The South took control of all of the items, and only put two into play, hiding four of them (which was allowed). This meant that only two could be captured, so they cold only lose the points for two. Also, two items would be easier to defend, especially coupled with the fact that they were held next to respawn points. No "locked in" items were removed from buildings at any time. The South were able to capture all of the jewels at the start of the game thanks to actually being, ya know, organised.
The downfall with the plan was that the respawn points ended up being used to heavily, costing them elimination points. The North won, but the South were the better team.
Your umbrella weilding ref, Cook$.