Since the front ring sits tight in its konus with a sizeable chuck of shaft against the base surface prohibiting tilt in the event of the lower front ring stem lengthening, your "on good, solid impact on the scope" would have the bend it upwards by about half an inch in order for the rear ring to bent open those two set screws.
Looking at the dimensions - this argument points to faulty installation.
I have no qualms with these mounts on a hunting rifle.
