Yes it is.
> You’re describing the State determining that Apple incorrectly reported where the sales tax should go
Failing to report as legally required is illegal.
> (no one is saying deliberately).
Sure, but that’s not germane.
> From what I was gathering there’s been a change in law regarding online sale tax in 2019 or so.
There was; mainly, from looking at the CDTFA information on sales tax (which calls out the 2019 changes) affecting sales through internet marketplaces and in some circumstances making the marketplace, rather than the seller-through-the-marketplace, the retailer for sales tax purposes, and requiring registration and use-tax collection by retailers in certain cases. The change doesn’t seem related to the Apple/Cupertino sales tax issue.