Gary, thanks for the link.
I think the credit is related to the total net tax you owe to colifornia for the year, regardless how much withholding is being taken month by month. For example, for a regular emplyee, a portion of your salary is withheld for each pay-check. if your net tax is $6k for the year, and your accumulated total withholding is $7k, you are still going to get the $3,333 credit for the year, so that your total refund (by april next year) will be (7k-6k) + 3.333k = $4.333k.
