Based on a few things, we were both right. Primarily I'm going to reference this (which corroborates what you said, except it claims 74 minutes):

https://en.wikipedia.org/wiki/Optical_storage_media_writing_and_reading_speed

Something called "Ask Leo" does say there's a high risk of a disk shattering when spun above 48x, which is apparently equivalent to 24000 RPM. However, I can't vouch for the credibility of this site any more than I can for the person who originally made that claim to me (except that I think it was my dad and he was usually pretty dependable).

https://askleo.com/what_does_the_x_in_a_48x_speed_cdrom_mean/

Apparently Mythbusters demonstrated that a disk will shatter at 30000 RPM but, as sometimes happens, their methodology was criticized. This, it seems, is because they spun the disk on a Dremel rather than in a more realistic environment.