As much as we talk about darwins theory and spectators standing at the apex of a corner, it's up to the race organizers and more importantly the coast guard to make the course safe for the spectators and the racers.
Even though I'd have the common sense to stand further away it's really not the specators fault. For instance, last year at the Pt. Pleasant race my sister wanted me to get closer to the course so she could get better shots. Even though I was a sweep boat, I refused to get any closer than I felt comfortable with.
The fact the spectators moved in afterwards just goes to show they didn't realize they were in danger until it was too late....