Well, definitely not a Blind U-Turn, you can seen Jill & Thomas courtesy off picture, besides B/S.
The assessment of C/S dropping from 1st to last here will probably happen and they'll probably be U-turned by N/V.
Just some speculation.
J/T, B/S will probably be on top part of the pack, hence Jill and Thomas deciding to U-Turn them, not just to make them mad, but to give them edge to the game.
Probably due to some mistake C/S will have dropped to the bottom pack and N/V will be neck by neck with them during Detour. N/V U-turn will then probably cause the elimination of Chad and Stephanie.