Yep. Hindsight is 20-20. But obviously if you need to evacuate and entire city. While the people are leaving the Military needs to be arriving.
If you were running across the freeway and got hit by a car, I would probably say you should not have done that. I would not call that "Hindsight".
From the national guard website:
The governor can call the National Guard into action during local or statewide emergencies, such as storms, fires, earthquakes or civil disturbances.
If you delcare a city of 1.5 million people should be completely evacuated, I would think that would qualify as an emergency. This was not just an emergency Monday, it was one Friday and Saturday.