Not how the law works. If I put a bomb in a box. It will explode if a certain pin is put in. And you ask ”can I open the box? What is the pin?” And I say ”here is the pin to open it” and the bomb explodes. Do you think I can claim they blew up themselves ?

Yes. Because law enforcement assumes there's bombs in boxes by default and defers to the bomb squad to understand the box before they touch it.

Why would the bomb squad trust the box owner to help them defuse it? To understand the issue, you have to construct a proper analog.