I picked up a copy of the BiTW 2004 video by Propwash at the last AMA show (mainly for the Flanker footage and my interview--cheeky endorsment
). In one scene you can see a Cessna transitioning the airspace overhead during one of the jet flights. There was plenty of airspace separation as seen in the footage, but there were airplanes flying overhead.
FTIW, I did see the Mooney fly over, but did not witness the reported near-miss. He was a bit low, but legal and the jets were a bit high. It ended being a sad situation for all involved, especially the jet flyers.
How warm does it get in Palm Springs in April?