I agree Cleasanta - aside from one thing - dogs do lie and you have proved it with your example. They do what they need to do in order to get what they want.
A dog going ballistic on a head halter is not necessarily in pain
My mums dog is outside crying like someone is murdering him - because he knows that will send mum running to his aide and let him in
Dogs don't knowingly "lie" but they do deceive in order to get what they want - as do we lol