What's normal after an unfill?

It's good you found it was a slip.  Keep in mind, you PC doc doesn't specialize in the band and "chest wall pain" IS an actual syndrome having nothing to do with the band.  

I know this is the pot calling the kettle black but you need to try to get back to proper band eating techniques in order to know when things are going wrong with your band.

I had a total unfill  three  years ago. My band was tightening up from allergies and just could not take the pain and pressure in my chest and head. Left all the fluid out for about 9 months. Have not had any reflux or pressure since. Started to re fill after 9 months and have only added half of what I used to have back. Have not had a  another fill in almost 2 years. Hope you get some relief