My guess is the paint sandwiched between the nut and wheel (acting like a shim or gasket) gave up the fight when things got hot, creating clearance where none existed when the paint was good, and the result was a loose nut (wheel).
Did the wheel come off in this case? They have safety devices in the nuts to prevent that. Could be something else went wrong.
Probably not to well known but a Pelican Parts neighbor (in the same neighborhood)
http://www.metalore.com/ makes most of the wheel nuts and sockets used in F1 (or did the last we spoke which was a few years ago). If still in the business, he would know what happened.