Someone who is Lying might exhibit hesitation and shifting posture as well as dilated pupils.
This is incorrect since this is one of the traditional measures. The fact that both may occur is no reason not to trust the "better" ones.
A practiced liar might have achieved great control over body posture and eye contact.
This is a reason to doubt the traditional indicators.
A person who is Lying might be aware that he or she is being closely observed for indications of Lying.
This is irrelevant. The "better" methods are supposed to compensate for this by avoiding behavioral indicators that one could correct for if they knew they were being monitored.
Someone who is telling the truth might nevertheless have a past history of Lying.