Monroe, despite his generally poor appetite thoroughly enjoyed the three meals he ate at the Tip-Top Restaurant, but, unfortunately, after each meal he became ill  The first time he ate an extra-large sausage pizza with a side order of hot peppers; the second time he took full advantage of the all-you-can-eat fried shrimp and hot peppers special; and the third time he had two of Tip-Top' s giant meatball sandwiches with hot peppers
Since the only food all three meals had in common was the hot peppers, Monroe concludes that it is solely due to Tip-Top' s hot peppers that he became ill
He fails to establish that everyone who ate Tip-Top's hot peppers became ill.