Similar things happen when you require fingerprints or retinal scans. "Well, I don't have a right hand anymore. It's in some hospital's incinerator."
And not having an override or bypass is a software issue. Designing a system that doesn't permit exceptions or overrides is bad software design.
I think his point is that the designers of the software would have been aware of this, but they weren't the designers of the system, who wanted software to do All the Things.
You cite three meaningful changes in biometrics: disfigured, loss of fingerprint and retinal issues.
In all three cases surely the right and proper thing do to is to get your details updated on the system ? It may even be a legal requirement for you to do so in the case of official ID documents.
Of course, if you have a temporary mismatch due to being injured on holiday that's different.
But for a permanent thing I just don't see why you would not just get stuff re-issued or updated.
The real world is messy.
I suggest you actually read my post, because its clear you did not.
If you had read it, you would have seen the phrase "Of course, if you have a temporary mismatch due to being injured on holiday that's different.".
I quite clearly excluded holiday injury.