If a claim for benefits is filed within two years after the injury, or, if death results therefrom, is filed within two years after such death, as provided in section forty-one of this chapter, then in any proceeding for the enforcement of such claim, it shall be presumed in the absence of substantial evidence to the contrary:

1. 1. That the claim comes within the provisions of this chapter;
2. 2. That sufficient notice thereof was given;
3. 3. That the injury was not occasioned by the wilful intention of the injured volunteer firefighter to bring about the injury or death of himself or herself or another;
4. 4. That the injury did not result solely from the intoxication of the injured volunteer firefighter while acting in line of duty;
5. 5. That the contents of medical and surgical reports introduced in evidence by claimants for benefits shall constitute prima facie evidence of fact as to the matter contained therein.