Well, TBH I don't hope anyone would have gone airborne with an FCC not completing is POST.
This confirmes (once again) that the changes done to implement inter communication and health checking between the two boxes and fixing this dubious AP disconnect issue, which must have something to do with the task scheduling, were in fact open heart surgery on these old architectures.
What could possibly go wrong?
To discover this half a year down the road - presumeably after the fix itself has been reviewed and was close to approval - is pretty embarrassing.
However knowing the timelines from comparable hot fixes in automotive I still think that this one is rather rushed.
With sound testing one would not expect these problems.
After all, these FCCs are no PCs where every unit is different with regard to hardware, user installed software and configuration.
In such a well controlled environment as transport category airplanes straight from the production line one should be able to do better, if testing and validation was sufficient.