Lightman gives the young boy Max some tips about how to ask questions when he interviews the couple he suspects are not really his parents. Don’t ask them questions that can be answered with a simple yes or no. That is one of the tips I always emphasize with police. You want people to use as many words as possible. The more words someone speaks the easier it is to determine if the person is being truthful; a pretty strong research finding. It is much easier to lie if you only have to say one word: yes or no. But in the courtroom in which juries have to evaluate the truthfulness of witnesses and defendants, the questions always have to be asked so that they can be answered with a simple yes or no. That is one of the many reasons why it is so hard to spot lies in a courtroom.
Max says that Lightman said in his book the best interrogations are when you can watch and don’t have to ask the questions. That is because having to ask the questions distracts some of your attention from observing everything the suspect is saying and doing. But sometimes it is crucial for the one doing the observing to be able to ask the question that pushes the suspect to stop dodging and directly answer. So it is ideal if there are two people doing the interviewing, who take turns as the need arises, as to who questions and who watches.
Lightman and Foster are certain Mrs. Knox is lying because she recalls a small detail from 16 years ago. While such details are not usually remembered, it is far from certain that such a memory would always be false. Poetic license.
Loker says Delicia faked anger because her anger did not include lowering her eyebrows and pressing or tightening her lips. He probably would be right, but the only reliable sign that anger is being faked is the absence of tightening or narrowing the red area of the lips. It is reliable because most people can’t make that movement deliberately, so it rarely appears in false anger. Most people can easily lower their brows or press their lips, if they remember to do so.
Covering Your Gonads
Covering your gonads might be a protective maneuver, but I would be very hesitant to tell someone who made that movement it was a sign he felt vulnerable. To extend that to explaining why Churchill put his hat in his lap is quite a reach. Where else can you put your hat if you are not going to wear it? But… It is not totally implausible, and it does move the story forward.