Movies are works of fiction not law. In America if you choose to temporarily waive your right to silence and speak to police you may at any point reassert that right.
I couldn't blame cinematographers for attempting to tell a story. But they are artists not lawyers.
You may talk to police that way in America but any good lawyer will tell you not to because the strength of the fact that your silence can't be used against you often will offend out weigh any defense you might argue.
When guilt must be proven absence of evidence is the defendant's friend.
7th amendment applies to civil suits. Judges may when common law doesn't govern. But that's limited. And criminal defendants must consent to bench trial by not contesting any of the facts.