I've got all solid mounts, this particular failure is nothing more than driver error.
On member days, we're only allowed to pass on the straightaways. Since it was Good Friday and there was a good bit more traffic than usual (and most of them V8's), I'd go out and tool around at 30-40% for two laps, hot pit and check tire pressures, and then go back out and hit the track hard. There's no reason for me to put extra steering effort into going all the way out to the edge of the track in an instance where I'm not powering all the way out there.