Based on local news reports and video, everyone was advised of the approaching storm and given locations to take shelter. It was less than 5 minutes after that announcement when a wind gust at the leading edge of the storm took down the stage. The actual storm wasn't predicted to hit for another 15 minutes or so.
Once the rigging came down, people from the crowd rushed forward and held up the rigging in hopes of preventing any additional injuries to those underneath it. There is also plenty of video out there of crew members directing bystanders in how to manually hold c-spine, and utilizing them in assisting to log roll people onto make-shift backboards. Yes, I am sure not all bystanders who attempted to help were actually helpful to fire and ems crews, but from what I have seen and heard, there were countless more who did listen to crews and were helpful in assisting with some basic things that needed to be accomplished.
Most of what a basic can do is simple first aid and common sense. You don't have to have a certification for either one of those. Granted, most bystanders aren't trained in structure collapse or triage (like you mentioned), but they were able to help in other ways, freeing up those that did have that training to do what needed to be done.
All critical patients were evacuated within an hour. I think that says quite a bit about how well the situation was handled.
