Kristie is a complete blank in this storyline. We already know that Phoebe and Kat don't get on, but why did Kristie vote with Kat before? I think we needed to know.
Anyway this episode continued the Kat/Phoebe rivalry and brought it to an end.
Phoebe did well finding the idol, but why tell people about it (and Kat who had already outed Rohan's idol). Very strange. The majority really had the say in who was going, so trying to win over Kat (no indication she would) or Kristie seemed pointless. Phoebe was lucky Kat didn't out the idol on her way out at the tribal.
Kat was playing this like it was a personal game of her v another rather than longer term strategy. I didn't get her remark at tribal that she had allied with the majority, the last vote didn't show that. Maybe that was to scare Phoebe into playing her idol. Just checking the end of the episode, we weren't shown Kat's vote, bad editing there. I assume it was Andrew. It looks like Phoebe was informed of the Kat vote, no indication of that beforehand.
The storyline is still 'Rohan sent himself home', but Kristie did that really I think. But she's not part of the storyline it seems. Andrew got a strange soliloquy at the end, like the villain he is meant to be. I'll assume that's meant to set him up for a fall, though that would be a bit too obvious for me.
... cheers.