Zero Trust is not really applicable here. ZT is about not implicitly allowing someone elevated access just because they have access to network and requiring exp

Zero Trust is not really applicable here. ZT is about not implicitly allowing someone elevated access just because they have access to network and requiring explicit grant based on the identity and other rules. Fastly's downtime seems to be caused by an automatically generated config that got deployed in production as a result of change requested by a legitimate customer. This happened to CF in its early days and I really doubt that ZT had anything to do with the fact that they do not have this kind of problem anymore. It's probably some sanity checks before they deploy updated lua scripts to their fleet of nginx's if anything.