While I believe body language & statement analysis can be useful tools, both are dependent upon the observer's subjective interpretation as well as the observer's skill in reading the signals.
Speaking from personal experience, as I've grown older (and hopefully wiser), I've learned to accurately detect the warning signs of a potential abuser, and I've counseled young women on how to recognize these same signs (both covert & overt) so they don't fall victim to abusive partners.
I've also learned to be aware of the subtle cues of danger (after finding myself in more than one life-threatening predicament over the course of my days). Gavin DeBecker has an excellent book on the subject: The Gift of Fear.
I don't discount body language analysis or statement analysis, because I believe we all use these innate tools in our daily interactions, whether consciously or subconsciously.
I think we need to use these tools wisely, though, and not use them as a stone to hurl at someone in the absence of solid, physical evidence.
