Most insurance policies, unless you pay for special coverage, does *not* cover damages incurred due to civil unrest, riots or looting.
I remember about 6 months after 9/11, my mailbox was stuffed with policy changes in really tiny print for all the policies I held that said ‘terrorism isn’t covered as of now’.
I left the insurance industry about 13 years ago. That was actually a happy day in my life. Did things change that much? In my day we covered on an "All Risk" policy such things as riot and civil commotion.
On the other hand, if I owned a business in Ferguson I would negotiate with my insurer to let me rebuild somewhere such that local denizens don't try to ruin me because of an event like this.
I don't know what happened there. I doubt Wilson was looking for guys to gun down. I doubt he was hunting for the most dangerous game.
I do know there must be somewhere to build a business where the locals don't blame me for something I can't control. I would ask my insurer to assist with that, maybe for a discounted payoff.