The bar attached to the upper frame is slotted so that it will slide upwards when the swingarm is compressed thus maintaining an unchanged hitch height (I learned this after a trial and...).
After viewing Red's pictures of the rear hand grab mounting bracket failure and taking into account the physics involved, I believe the failure was caused a passenger's weight being multiplied backward into the trunk by the driver's acceleration beyond that of a little old lady heading out to church.
I'm fully confident that without a passenger the trunk will be fine regardless of the speed or acceleration (so long as the trunk isn't overloaded), but since I occasionally may have one, I'm creating a 6 point mounting system for trunk and side luggage. Don't hold your breath though as my truck's oil pump has gone out (hopefully that is all).