It's called artistic license. Many dramas, and even comedies, revolve around artificially removing certain options either through plot twists or just ignoring them. The movie would be kind of boring if they hadn't strategically "forgotten" that she could just order extubation herself, then there'd be no moral quandry for Eastwood's character to navigate.
I've been on a deus ex machina kick since I learned the meaning of the term a few weeks ago. It can be pretty funny when you look for it.