As with many TED talks, high on anecdote, low on empirically validated substance.
If you want to learn more about lie detection, read Paul Ekman's book "Telling Lies".

Pseudoscience dressing itself as science by attacking the more obvious pseudoscience of Lie To Me, Law & Order, etc. Many things she states as universal facts are merely highly probable under certain circumstances. Most blatant factual error: @9:50, she states that we cannot consciously contract the "crows' feet" of our eyes to fake a smile. I knew this to be false, but proved it by watching comedy in front of a mirror until I laughed, then waited to return to my normal gloomy self, then faked a smile--complete with crows' feet as when I was laughing! If you are a true scientist, you probably already know to beware of what soft scientists call "science"--such certainly applies here. If you are a layperson who has never heard stuff like this, it could be useful to open your awareness to the fact that we can consciously hone in on clues in communication. But they are just that: clues. The soft sciences have horrible definitions of "proof," and so present conclusions as "facts" as solid as 2+2 = 4 when the conclusions are mere conjectures. Listen to what they say and reflect on it, but don't believe its face value.