No one has said Zimmerman broke no laws that night, this case did not decide that either. The only thing this case decided was that he was innocent of the laws he was charged with, according to the evidence and sworn testimony. That is all.
What laws did he break? He was lawfully carrying a gun. It was shown (via his acquittal) he lawfully used deadly force to protect himself. I'm curious what laws were broken? Only law I can see broken is assault and that was (most likely based on testimony) Martin who broke that one.