What happens to an alignment when the owner is blackmailed to do evil/good acts?

[Sith_Happens]

But it's not the Good Person's place to sacrifice the life/well-being of his loved one. Me feeding my best friend to a lion so I can escape is NOT a Good Sacrifice, even though I'm sacrificing my close friend.

This isn't about feeding your friend to a lion to spare yourself, it's about feeding a random bystander to a lion to save your friend (or rather, if you're Good, not doing so).