I'm sure since the last eviction where despite Brian saying the first four were saved in no particular order, Sara has it in her brain that because she was first to be told she was saved, she got the most votes.  Since then she's become more confrontational, especially having downed a lot of booze.

She was owned by Deana in that conversation - she makes sweeping comments and then fails to back up or give a reason for why she says something and then gets argumentative when she's called up on it 

It's funny how we all see things differently, it seemed to me that Deana was being very aggressive. I think that Sara is the nicest girl in the house.