Mo. Rev. Stat. § 376.800

Anything in the law to the contrary notwithstanding, no misrepresentation made in obtaining or securing a policy of insurance covered by sections 376.770 to 376.800 shall be deemed material or render the policy void, or constitute a defense to a claim thereunder unless the matter misrepresented shall have actually contributed to the contingency or event on which any claim thereunder is to become due and payable, and whether it so contributed in any case shall be a question for the jury.