Rarely are the parents given guidance on how to handle their own feelings about their child's problems and actions and many parent-child arguments and conflicts ensue which only worsen the child's shame and confusion.
We have all done it. We try to say something that is helpful and reassuring. We try to say something that will take away someone's fears or doubts. The problem is it usually doesn't work. And sometimes reassurance does the exact opposite of what we intend.
I draw a big line between little lies and big ones. Serious lies -- the big time betrayals of trust -- are probably never good for relationships of any kind. Little lies are often a different matter entirely.