Volunteer choked up about euthanizing all the cats at animal shelter

Sullivan County Animal Shelter cats now dead
All the cats (up to 60) have been euthanised at the Sullivan County Animal Shelter because a kitten adopted from the shelter was diagnosed with feline panleukopenia (feline distemper or parvo).
The other cats were evaluated and the decision to kill them all was made.

Animal shelter volunteer tears up at a meeting
However, one volunteer referred to ‘Kitty’, a cat recently brought in on the death of the owner, and said she did not have to be euthanised.
“Things could have been handled differently. The outcome could have been different” – shelter volunteer
They are saying that the shelter director was not experienced enough.
How do they decide to kill them all? They were playing safe I guess and starting afresh. Kitty could have come into contact with the infected kitten and perhaps the shelter felt they did not have the time or resources to monitor her for signs of the infection. However, they do have foster carers working with the shelter.
Resources and experience
Perhaps I am being naive and impractical but at least some of the cats could have been saved if sufficient resources were in place. Couldn’t they have evaluated and monitored all the cats? Apparently not. This a complicated matter. With unlimited resources lives could be saved but it appears that the practical and pragmatic albeit very sad decision was to start again by clearing out the entire shelter. It’s brutal and perhaps a factor is the relatively low worth of the lives of shelter animals in the eyes of some.
Minimize contagion
Feline distemper can be minimised by vaccination on intake, a good disinfecting protocol and quarantining cats on intake for evaluation. Perhaps this is too demanding for some shelters or am I missing the point?
The quarantine strategy is one where all cats with unknown health status on intake are held in quarantine for long enough to evaluate their health before placing them among the general shelter population.
https://pictures-of-cats.org/pool-shock-is-an-effective-and-cheap-disinfectant.html