I think (hope) what happened was the Cowboys won the first leg and received the 2 express passes. They gave one to Caroline & Jennifer, a team they considered weak, during the next leg. Maybe during the task the country singers were having trouble with.
Legs pass by and Carolin & Jennifer avoid elimination several times, even coming last in a non-elimination leg. Then in Leg 10 Seville (maybe), Caroline & Jennifer and Jet & Cord were in last. A U-Turn appeared and the country singers got there first, U-Turning the team that helped them in the early race. Then Jet & Cord started whining that they kept being U-Turned because the other teams see them as a threat, and not because of the obvious fact that they are the only team behind the team U-Turning them
The country singers gets second to last and the cowboys checks in last, and hopefully it's an elimination leg! Caroline & Jennifer then outsmarted another team to get into the finale, but their luck ran dry during the final memory challenge, kicking them down to third
I hope Leo & Jamal, Dave & Connor, Caroline & Jennifer, or Brendon & Rachel won this time (basing my judgement on the teams during their initial seasons).