Clearly his production assistant and editor had not studied up on all the signs that someone is lying. I wouldn’t have thought of that... I’ve always heard/read that the persons eyes go one way for memory (up and left for truth) and one way for creation (up and right for lies) and I did notice BM very expertly kept his eyes focused on who was directly in front of him, so much so you could see the effort /concentration in the wrinkles on his forehead.
I thought the head shaking was “this can’t be happening” until someone on here pointed out that he did it when he said specific things like “We love you, I want you back so bad” I’ve definitely learned a new technique for judging if someone means what they are saying.
I don't think anyone was in front of him. I think he set the camera up, himself. The reason I think this, is that when there's a person behind the camera, there are typically micro-flickers (or larger flickers) of the eye up toward that person, to check their response. One way that people assess their verbal performances is by checking the micro-expressions/expressions of people nearby. He never wavered from staring right at that camera lens (presumably a phone - perhaps an iPad?) I am guessing he's recorded himself before, but I also think the clip looks as if it had the first part cut off - and perhaps the last part. I think this is a family where everyone probably shared video among themselves and knew how to do this. I have an app on my phone that lets me chop video files (but I've never used it, so far).
The part about people's eyes going to a particular place while they try to remember is highly variable. It's not a human universal, it's largely cultural/learned. There are many expressions that people use when they are thinking about things.
But I agree that his ability to keep his eyes completely focused on the camera is a well-studied device. This is unusual. Even when told to do that, most people will waver. I am cynical, today, about his furrowed brow. Yes, he was concentrating, but if he was using the forward facing camera on his phone, he was also able to observe his own face and let's face it, a furrowed brow (and the ability to make that many furrows) is something character actors know to use to denote "concern," "worry," etc.
I think the head shaking means several different things. Combined with the furrowed brow, it's kind of a "Please, don't" expression (Please don't hurt her, Please don't let this be happening, Please don't let time keep moving forward) but what's missing is any firm expression of what most would be feeling (determination, anger at the abductor, a fixed idea about doing everything to find one's wife, expressions of what one is actually doing to find her, etc). For example, "I promise you, Suzanne, that I will find you, no matter how long it takes." The expression that would accompany this would be very different - and if he were still shaking his head in denial while uttering it, that would be truly bizarre. The fact that many of us also read "Please don't believe anything I say" is not intended, but also not a coincidence. He's selling something that he's not saying.
He wants to make sure that he comes across as worried, somehow paralyzed by fear and worry, and therefore incapable of action. It's a good enough image to leave in the minds of LE and potential jurors, IMO. Best he could think of, anyway.
We know from other sources that he then apparently defies LE (who asked firefighters not to search for Suzanne) and goes and organizes a search.