It is, though, but it depends on what you value. Loyalty/supporting one's friends/family is more important than any other principles/values, but it's also context-dependent.

That's a good point. It's also about acceptable degrees. Your friend rapes or murders someone? Fuck that guy, off to jail with you. He does something more minor but still immoral, like steal? Yeah, I'll probably try not to involve the law, and help him make it right or something, while keeping him out of trouble...even though he did wrong.