premise: Seth gets sick<br>Seth is eating his favorite burger. He enjoys it. After about 30 minutes his stomach starts feeling weird. Seth begins feeling sick. Moments  later Seth vomits all over the place.
hypothesis: Seth vomited up the hamburger. 
reason: If Seth vomited 30 minutes after eating, he threw up the hamburger because it was still on his stomach.  It doesn't mean the burger was the cause of the vomiting, but being the thing Seth ate very recently, it would have been thrown up.  