After a while in the hobby you learn to spot those guys pretty quickly. Texans tend to be pretty "live and let live" about things, so when one of those guys show up and make it clear that they don't want any help we just sit back and enjoy the show, taking proper precautions in case the crash happens on the wrong side of the flight line. We generally don't go help the guy pick up the pieces either unless we think he isn't going to want any of it and there might be some useful stuff in the wreckage.