Now let's say that instead you threw the keys to your unbreakable safe to your friend across the Atlantic Ocean. And you say that you didn't know that the people entering were cops. And your friend won't give the keys back. The evidence may exist, you cannot access it, neither can the police. The court has no jurisdiction over your friend and you have no authority to force your friend to give you the keys back.

At that point, whether you are in contempt or not depends on the answer to the question "did you know that the cops were entering to look for evidence before you threw the keys?" Whether the judge holds you in contempt or not is a function of the free choice of the judge and is not related to the answer to the first question (though whether or not the judge should hold you in contempt is a function of what the judge believes about what you believed).