Found it in our club database. It was April 10th 2004.
http://www.lonestar-mvpa.org/events/2004/04_burnet.htmIn the picture list on the bottom left. Caption says it was a Wildcat. Can't see much in the photo but can see what appears to be the Wildcats type of landing gear.
In regards to Charlie Hillard. It's always sad to lose an old warbird but when the pilot is lost as well it's makes the warbird loss seem trivial.
A few years back I was volunteering at an airshow in Burnet Texas. About an hour before the show was to start a late spring cool front blew in. The vendors tents were blowing all over the place and a lot of aircraft that were still en route opted to turn around and go home. There was a F4F Wildcat (or maybe a Hellcat) that was close and the piloted decided to come in. He ground looped at the end of the runway and ended up flipping the aircraft over. The damage didn't appear too bad. I've never heard what happened with that aircraft. I assume it was fixed back up.