But that's taking the second derivative of the situation. Most people can barely take the first.
The point is that it's a ridiculous nonsense statement. It can be applied to anyone about anything. I have no problem with someone believing he's a spy based on evidence or even intuition. I do have a problem with a tautology being used as evidence, or to sway opinion.
If the person is trying to deceive you they will attempt to deceive you. Well, duh.
We can do this all day...