I agree with Taxing Matters.
While the driver getting out of his car and then back into it and hitting your car clearly sounds as if it's 2 separate accidents, if the driver's insurer continues to deny the claim when dealing with you, your recourse is to either sue the driver who hit you (and as it's in California you can likely sue in Small Claims Court for up to $10,000) or report it to your own collision carrier, initially absorb the deductible, and let your insurer argue with the other driver's insurer. The other driver's insurer will probably then conclude (as it should have done for you) that it was 2 accidents and pay your insurer which will reimburse your deductible.