This is Susan's bio claim to fame as a lady with a masters in psychology:
"With a wealth of experience and expertise, Susan Constantine is renowned as the world’s premier authority in the areas of detecting deception and trial consulting – body language analysis. She is a sought-after expert, nationally and internationally, who is often requested by the media during highly publicized trials to seek clarity through her meticulous analysis.
"In addition to appearing regularly worldwide on television broadcasts, radio shows & print publications; she also delivers powerful keynote speaking events while offering consulting services based upon her acclaimed expertise on communication and body language.
"Her years of experience have provided her the opportunity to serve government and political leaders, legal and corporate professionals, and celebrities.
"Her heart is to serve others by revealing the truth."
The other guy, Greg Hartley, a former interrogator in the U.S. Army, doesn't have a bio. He most likely took the six-week interrogation training classes and read the yellow field manual a few times; maybe took the non-com advanced class as well. Nothing is stated about his training level or experience with 'reading' civilians for truthfulness. He uses the classic eye shift moves that supposedly yield insight into a person's truthfulness as Susan does.
Together, these two can tell you what you want to hear for a few hundred dollars, and for a few thousand dollars, they will train you to make similar deductions in a weekend seminar.
Add that to the fact that this was a Fox-hired interview, and there you have it: Harris was uncomfortable about the interview. So what's new about that?