In dealing with any insurance claim, in practice, the question of onus is probably the most important one. This is but common sense; anyone who claims for something faces the burden of proving it. It is general legal requirement that the insured must prove that a particular loss event is covered under the insurance policy. In the event the insurer refuses the claim in terms of one of its policy exclusions (see article on ‘Policy exclusions and endorsements’) then it is up to the insurer to prove the events that fall under this particular exclusion.
For a practical example of ‘onus of proof’ consider the policyholder that crashes their motor vehicle on the way home from a late night corporate function. All evidence supports the insureds claim so such accident is covered under the policy so the insurer will have to honour the claim as valid.
If however, the insurer wants to refute the claim based on a suspicion that the insured was driving under the influence of alcohol (an exclusion under any policy) then it will have to be able to prove this suspicion beyond a reasonable doubt.