Production looked at BBCAN to figure out how to keep the vet in the house. They knew damn well the early popularity vote would be for Paul, so they give him 3 week immunity. Mission accomplished. They keep finding new ways to have production manipulation.
That being said, the temptation twists seem to be working out quite well. They're really stirring the pot and keeping the house paranoid. The goal of production should be to keep them uncomfortable and prevent the mutual house voting and everybody thinking this is a fun summer vacation with games where most everybody gets along. The ying yang consequences of the temptation den and the strategy screw jobs make for some interesting TV. The Den of Temptation looks like it's going to be the most influential room in the house.