You sold your chametz to a non-Jew, directly.
During Hol Hamo'ed, the non-Jew comes to your home and says he wants your $500 single malt scotch, and he writes you a check for it. He walks out with your scotch, getting happily drunk along the way.
Can you take his check during Pesach, or is it in some way benefitting from chametz? If it is, consider that a check provides no actual benefit until you cash it - could you hold onto the check but not cash it until after Pesach.