Really, Erik, I fail to see the connection. Unnecessary code had nothing to do with rescuing the vehicle to which you refer.
The "we fly what we test" mantra resulted in a debug feature of the OS being present in the "flying" code. Thus the failure could be diagnosed and, becuase some programming code was there from the test it could be reprogrammed.

You refer to "unnecessary" code, that is one thing, what on earth is the problem with "uncalled" code.

Erik