It sounds to me like this group is not your normal group of refugees. If you want to give them a home then you should check with your state prisons and see if they have some extra beds.
It's an Orleans Parish bus. That's NOLA. These are refugees. No food, no water, no home, flooding, roaming gangs, no information, thousands and thousands and thousands of wandering refugees in similar dire straits. Can you honestly say that you wouldn't take such a chance to get out, especially if you have family? There were children in that group.
However, there is a decent chance that a bus with keys was hijacked. That is a problem. But this isn't a simple cut and dry issue. As far as they knew, these people were facing death. Given the difficulty in getting enough troops and resources into the city, can you really say you wouldn't be scared to death that you wouldn't survive without taking drastic action?