Fascinating. And so simply put. It really makes you look at using body language deliberately as a writer, and target the movements for a scene. I like what he says about evidence at the end.
A while ago, I read a book about body language. (Left of Bang - It's written by two special forces guys and is all about profiling and reading body language to stay safe. If I remember right they also touch on spotting the offenders during unfolding events) and it shows how little control we humans have over how we come across, and that trying to control our behaviour, shows something.