Most likely was a lack of skill by the operator. Penn is much more forgiving due to a larger head diameter and the 4 legs stick out about 1/4" on each side of the cylinder after it has been tightened. Hole diameter does not have to be very close. I think the tool you used is better than the one I have. The allen wrench would hold the rivnut in the hole for overhead installation. With my tool it uses two box wrenches so upward pressure is not possible.