73kts will Weathercock most things if they are parked out of wind, in my experience the only chance you may have is if they are double chocked on the main gears & nose with brakes on.
I have even seen Aircraft Weathercock after the wing has been lifted causing the gear to be lifted out of the chocks, even with brakes on on a wet Apron.
I am not keen on the wooden type of chocks seen in photo's Flames earlier post in fact we refuse to use them where I work, due to weather conditions we experience from time to time.
It looks to me like no one had a chance at preventing this as there was no real warning, of the likley Gusts in the Squally conditions,or the Tornado & no time to set brakes double chock & put ballast on aircraft, tie things down etc.