If it was food poisoning I'd have had no issue, but the passenger was the one that refused to say what was making her sick. I didn't want to see her medical records, just wanted to know if it was something she ate or some kind of contagious deal. According to some it's the roll of the dice and if someone chooses to get on the plane with a contagious disease it's just part of flying? As someone else said, if it was randomly assigned yes, if someone asks me if I mind I'm going to also answer YES I mind.

For reference purposes she was sitting about 5 rows in front of the bathroom, in a middle seat. What's the difference in her simply trading with the person she's already sitting next to and taking the aisle?

I know I'll get jumped on for pointing this out, but she spent the rest of the flight with her legs crossed playing games on her phone. I still think there is a greater than zero chance she just wanted to sit in the bulkhead seat. On this plane it was the kind with unlimited legroom. She asked specifically for the seat on one of the sides of the plane, not in the middle bulkhead section that has the wall in front.

The only reason I can think for being asked vs. told was that we were both Sapphire on Oneworld. The gate agent made a comment when we checked in that she would try and keep the seat blocked due to the light load. I fully understand that it's never guaranteed.