CA code for ducting materials

[Corinne Moore]

Hi All,
I am just about to close on my first rehab - it has been a disaster. More on that later.
The buyer inspector has come up with 2 issues and I need help in deciding if he is being picky!
The dryer vent is not solid ducting and will have more than 2x90degree turns, if we replace it with Solid ducting. (I do believe that solid ducting is to code, so we will fix this.)

The big issue is the upstairs bathroom (which we did not touch) is venting into the attic with flexible ducting. We extended the ducting to the outside, but the inspector is insisting on solid ducting! Is he right or can I push back?
HELP