The provisions of Sections 995.1, 995.2, and 995.3 permitting the commissioner, in certain situations, to examine a person operating under a contingent or retrospective commission arrangement with an insurer at the expense of the insurer, and the other provisions of this article, shall not prevent the insurer from making a contract in advance with such person that in such event the person will reimburse the insurer for such expense. If in the course of examining such person the commissioner finds such person also operates under such contingent or retrospective commission arrangements with other insurers, he may prorate the expense of examination on an equitable basis among all the insurers so dealing with the person.