Venn Diagram Defense
Let A be the set of food made unkosher by normal kosher laws.
Let B be the set of food made unkosher by Passover laws.
Let x be pepperoni matzah pizza.
So although x is in A, it is not in B QED.
If Moses were alive, he would probably beat me with a stick, but pepperoni matzah pizza is too good.