It might make an awesome movie, but if it were expected behaviour, it would defeat the point of the injunction. In fact if rationalists were expected to look for workarounds of any kind it would defeat the point of the injunction. So the injunction would have to be, not merely to be silent, but not to attempt to use the knowledge divulged to thwart the one making the confession in any way except by non-coercive persuasion.

Or alternatively, not to ever act in a way such that if the person making the confession had expected it they would have avoided making the confession.