Cal. Code Regs. tit. 4 § 1558
The placing judges shall occupy the placing judges' stand at the time the horses pass the winning post, and their duty shall be to place the horses in the order of finish and display results. If the photograph of the finish of the race indicates a close finish, or the placing judges are not unanimous as to the correct order of finish, the photograph shall be submitted to the stewards for examination and for concurrence on the result before the order of finish of the race is displayed or announced. In the case of a dead heat, or disagreement as to the correct order of finish, the decision of the stewards shall be final. In placing the horses at the finish, the position of the horses noses only shall be considered and not any other part of the body.
Cal. Code Regs. Tit. 4, § 1558