If you were being questioned by a police officer and your life was in immediate danger ie a tornado was coming could you run away?

Probably not. If the issue was serious enough to interest the police at the time, it is likely that you would be required to remain and answer.

Usually something like this would be measured by a 'reasonable man' test, meaning 'how would a reasonable man act' in the situation. It is also likely that the court would find your action (running) to not be reasonable if a reasonable man (the officer) felt it was not necessary to run away. If you have reason to believe that the place you are in is unsafe, you should inform the officer.