In California State Auto. Assn. Inter-Ins. Bureau v. Jackson (1973) 9 Cal.3d 859, it is stated (at p. 869): ". . . We consider the purpose and intent of the exclusion in Insurance Code section 11580.2, subdivision (c)(4). We think that its purpose is clearly to shift the cost of an industrial injury sustained by an employee, as the result of the negligence of an uninsured motorist, from the motoring public (who pay the premium for uninsured motorist coverage) to the employer or workmen's compensation carrier. In other words, the uninsured motorist coverage, the cost of which is borne by holders of automobile liability policies, is withheld and the burden of liability falls on the employer or his carrier at least to the extent of compensation provided under workmen's compensation law."