Saab Dastard - do you mean 'aileron reversal' or 'roll reversal'?
At high AoA, the F-4 Phantom suffered hugely from roll reversal if the control column was used to roll the a/c. So much so that the phrase "If it buffets, use your boots" was often heard. I recall quite clearly the 'High AoA' handling trip I had to do with the Sqn QFI - including a 360 deg 'rudder roll' maintaining 19(??) units AoA...
Nothing to do with wing stiffness, this was purely an aerodynamic blanking effect. The F-4 used aielron and spoiler to roll; at high AoA the adverse yaw from the downgoing aileron was considerable and the upgoing spolier was blanked from the airflow...
Modern FBW takes care of such unpleasant quirks, leading to 'carefree handling' throughout the flight envelope which would have been totally impossible in older jets such as the F-4.