B17 Texas Raiders, Final flight

Like many of you who may read this post, I was shocked and in a state of disbelief to learn of the mid-air collision between the B-17 Texas Raiders and the P-63 King Cobra.  There isn't much I can say that you haven't already heard or read but this should have never happened or even been a possibility especially in this portion of the show.  I cannot recall having seen this pattern used at the many airshows I have been a part of or spectator. I was not at this show but based on the initial reports, the planes were flying somewhat of a figure eight pattern instead of the racetrack I normally see.