With a degree of discombobulation, I imagine. I can't see any causal mechanism by which buying insurance would cause you to live longer, so unless the salesman knows something I wouldn't expect him to, he would seem to have acquired an unreliable belief. Given this, I would postpone buying any insurance from him in case this unreliable belief could have unfortunate further consequences* and I would reduce my expectation that the salesman might prove to be an exceptional rationalist.

* For example: given his superstition, he may have allotted inadequate cash reserves to cover future life insurance payments.