I'm no lawyer (thank goodness), but my understanding is that his actions would be perfectly legal under U.S. law. You have every right to save your own life, and no obligation -- under law -- to save anyone else's life if it puts your life at risk.
Hence, in an incident like this, it becomes a matter of personal values. If you value your own life above anything else, you're free to make the same choice as this teacher did. If, however, you believe that you couldn't live with yourself knowing that you let a classroom of children die to save your own life, you might make a different choice.
Ah, he is speaking of the teacher who scarpered during the earthquake. That clarifies things. When he wrote “ran before his students and declared his view of personal liberty and freedom regardless his teacher indentity”, I thought that the poster was indicating that the teacher delivered a verbal treatise on personal liberty. My mistake.