Seems a common occurrence FH....
As in most things....if there is not air between you and the ground....there is not enough air between you and the ground.
The real question is why did it happen. What was done that should not have been....and what wasn't that should have been done?
It does seem interesting that the 22 puts out enough wake turbulence/prop rotor wash that it can cause an upset in another 22 following behind it.