California Code, Government Code - GOV § 21166

If a member is entitled to a different disability retirement allowance according to whether the disability is industrial or nonindustrial and the member claims that the disability as found by the board, or in the case of a local safety member by the governing body of his or her employer, is industrial and the claim is disputed by the board, or in case of a local safety member by the governing body, the Workers' Compensation Appeals Board, using the same procedure as in workers' compensation hearings, shall determine whether the disability is industrial.

The jurisdiction of the Workers' Compensation Appeals Board shall be limited solely to the issue of industrial causation, and this section shall not be construed to authorize the Workers' Compensation Appeals Board to award costs against this system pursuant to Section 4600, 5811, or any other provision of the Labor Code.