Dr. Mehmet Oz testified before the Senate's Consumer Protection Panel on Tuesday. Senator Claire McCaskill grilled him regarding some of his claims of the effects of dietary and health supplements on his TV show.
Towards the end the video above, it cuts in with Dr. Oz laughing (3:12).
Dr. Oz then displays an "Inward Lip Roll" (ILR) at 3:16 - this in an effort to suppress his previous laughter. The ILR is very commonly used by the subconscious to suppress strong emotions (positive or negative) when they are deviating significantly from baseline and a need to avoid an emotional crescendo.
Dr. Oz simply doesn't want to laugh as he is being scolded.
A fraction of a second later (still 3:16) Dr. Oz displays a "Tongue Jut". This nonverbal indicates he believes he's been bad by laughing out of context.
Throughout the other portions of this video (which is not inclusive of his entire testimony), while Dr. Oz does display anxiety (normal for context during any testimony) - his sincerity quotient is high and specifically he is not lying. He believes what he is saying.
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