I thought it was in Natalie's best interest to keep me around, and that's one of the reasons why I didn't play the idol. I just hope it comes back to haunt Natalie for making such a dumb move and voting me off. She's gotta be totally naive to think that Parvati, Amanda, and Cirie would take her to the final two or three instead of one of them. It was an idiotic move on her part. I don't know where she was coming from.

That's from Jason's Buddy TV interview.
Would Jason say "final two or three" if there was a F3 as is now customary? Probably not.
He also thinks Amanda would vote for him over Alexis or Natalie if they were the F3. Which confirms dislike between those girls, which means Alexis and Natalie probably would never vote Amanda either.