I can't see why you claim it's a stronger result. In the AI box experiment, the power is entirely in the gatekeeper's hands; in an interrogation situation the suspect is virtually powerless. This distinction is important because even the illusion of having power is enough to make someone less susceptible to persuasion.

Plus, police don't sit down with suspects in a chat room. They use 'enhanced interrogation techniques', methods such as an unfamiliar environment, threat of violence (or actual violence in some cases), and various other threats. An AI cannot do any of this to a gatekeeper unless the gatekeeper explicitly lets it out.