(b) In the event a work-related illness or injury renders an individual employed pursuant to the provisions of this article permanently physically or mentally disabled, the applicable law-enforcement agencies' disability coverage through the workers' compensation division shall apply, and the individual's existing pension shall be recalculated as though the disabling event had occurred coincident with the individual's original retirement. Any change in benefits resulting from this recalculation may not be retroactive in nature.
(c) The provisions of this section do not apply in the event a person employed pursuant to this article is disabled because of some cause or event which is determined not to be work related.