[JRTJH]

Someone who "touts the cause" of that accident and how to prevent it really needs to spend a few minutes looking up the payload, GVW, CGWR and towing limitations of the Excursion. From the emblem on the door, that appears to be a diesel Excursion. They were "notoriously" known to have payloads significantly less than the "truck cousins" from which they evolved. Payloads in the 900-1100 range were not uncommon. Looking at that trailer, no matter which hitch was installed, the tow vehicle was "overloaded" and, with all the "stuff" mounted on the rear bumper rack, I'd strongly suspect that the tongue weight wasn't appropriate and, if it was in the 10-15% of total weight range, with that much "counter weight on the rear, then the Excursion was likely to have been "critically overloaded"....

While a Hensley/ProPride hitch can prevent sway (literal interpretation) it can't keep a "stupid driver in his lane" nor can it prevent that same driver from creating a series of circumstances that lead to the inevitable.