§ 605-f. Disability benefits; certain disabilities. Notwithstanding any provision of this chapter or of any general, special or local law to the contrary, any member who is a county fire marshal, fire marshal, supervising fire marshal, division supervising fire marshal, assistant chief fire marshal, chief fire marshal, assistant fire marshal, or fire marshal trainee employed by Nassau county who contracts any condition of impairment of health caused by diseases of the heart, resulting in disability or death to such county fire marshal, fire marshal, supervising fire marshal, division supervising fire marshal, assistant chief fire marshal, chief fire marshal, assistant fire marshal, or fire marshal trainee, presently employed, and who shall have sustained such disability while so employed, shall be presumptive evidence that such disability was incurred in the performance and discharge of duty and the natural and proximate result of an accident, unless the contrary be proved by competent evidence; provided, however, that prior to entry into service, such county fire marshal, fire marshal, supervising fire marshal, division supervising fire marshal, assistant chief fire marshal, chief fire marshal, assistant fire marshal, or fire marshal trainee successfully passed a physical examination which failed to disclose evidence of any disease or other impairment of the heart.