Cal. UIC § 13071

If the employer, in violation of the provisions of this division, fails to deduct and withhold the tax under this division, and thereafter the tax against which the tax may be credited is paid or the taxpayer reports to the Franchise Tax Board the wages or gross income against which the tax would have been imposed, the tax so required to be deducted and withheld shall not be collected from the employer, but this section shall in no case relieve the employer from liability for any penalties or additions to the tax otherwise applicable with respect to the failure to deduct and withhold.