It kind of reminds me of Jesus healing the man with the shriveled hand (Mark chapter 3).
Sometimes we can get so focused on the legalism and the law, that we forget that God's primary interest is people.
Matthew chapter 12 details this event also:
Your question kind of reminds me of the question they were asking (although they weren't asking it to prompt discussion or debate, they were asking it to condemn Jesus). "Is it lawful to heal on the Sabbath?"... "Is it lawful to tell a lie to save a person's life?"
God looks at our hearts and our motivation. If the reason we're lying is to deceive for selfish gain, then there is nothing moral about that but God expects us to do what is right - to save life when possible.
Actually, the more interesting question from my perspective is more in the practical application of this - if God is more interested in saving life, under what circumstances would it therefore be ethical/moral to lie? I'm not attempting to turn this into a debate about the death penalty or abortion, but for example, if someone were a witness in a trial for a capital crime, should they lie to save the life of the accused? Should someone strongly pro-life lie about abortion to save the life of the unborn? I don't want to hijack the debate here and turn this into a debate about either of those issues, so if you want to mention either of those circumstances, don't attack the premise of the life argument, merely whether or not someone who believes life begins at conception would be obligated to lie - not whether their views on the commencement of life are valid. Personally, I don't think that in either set of circumstances, someone would be justified to lie.