[USNBandit]

If the tab failed as it appeared to do the pilot would encounter a sudden aft stick force. I have never flown a P-51 so I don’t know what the control forces are like in that aircraft.

[GBA]

Just speculating, I wonder what was going on immediately prior to separation. Perhaps a cable broke, tab flutters, then it broke off? What does that do to control at 500 mph, a few hundred feet agl, in a steep turn?

If possible, I think you're supposed to pull up for altitude, out of the race and try to figure things out. But, if the elevator's gone or if just one side is functional or asymmetrical?