Retirement tax questions

Ok so here’s an interesting twist for you all:

 

I failed to report my 401k withdrawal at all upon originally filing my 2020 returns (long story), so I recently got a letter from the IRS and subsequently used turbo tax to refile both my fed and state (CA) returns (each accompanied by a lovely bank cheque of course, ugh).

 

Today I received a REFUND from CA tax board of the exact amount I’d sent with my state re-file. 

This seems to indicate perhaps I don’t owe state tax on the early withdrawal at all - only federal? 

Surely that can’t be right, but I’ve never known CA FTB to ever make a mistake. 

Any experts here have thoughts on that?