Now that's a level of pedantry above and beyond! One single letter!
It's still named after the state, n'est pas? We're not talking a Humboldt vs. Humboldt's situation where the whole meaning changes are we?
Incidentally, IUCN (one of the few sources with standardised names for mammals) uses Californian under 'Common Names' but California in the text - so I'm not the only one confused!