It's been a while since I worked at Apple, but back in the day the entire OS X Server team made extensive use of kerberized NFS shares for moving around large files...
...the last version of Server shipped in 2021 (and the last real version shipped almost a decade before that).
Apple was still using Kerberos when I was there not that long ago.
Hmm, the more I think about I think you’re right, they likely still do use kerberized nfs, but I think the auth layer they use is… different. Without giving too much away, the internal SSO software ends up either wrapping or providing Kerberos tickets in some way, so I’m imagining that code path doesn’t panic.
In fact that’s probably the clue… everyone internally at Apple using krb5 auth with nfs is probably using the internal SSO software and the code path for “vanilla” Kerberos (ie. Ticket Viewer.app and so on) has zero testing. Maybe I’ll write that into the next crash tracer report I type up :-D
If you want a slightly different black hole to send your report to, you could use Feedback Assistant: https://developer.apple.com/feedback-assistant/