Hypothetical: During the Pesach holiday, a non-observant person walks into my house with the loaf of bread he just bought, and proceeds to use my regular knife and plate to make a sandwich. Clearly, he has transgressed.
Question: Is a problematic status regarding general kashrut incurred by his transgression regarding Pesach? I know that a Pesach-plate can lose its Pesach status, and a knife would have to be "rekashered" to be replaced in the Pesach fold, but is this same loss of status present regarding the general kosher-ness of the stuff he used (assuming kosher ingredients, just not 'kosher for Passover'). Has he affected the kashrut status of my dish and knife for after Pesach by using ingredients that were kosher but not kosher at that moment?