So this happened...........
I had drug the rear on a 2 other occasions and caused no rear bumper damage like this and while I didn't do it on purpose and I don't like when it happens this one particular instance it was the spare tire located directly underneath that hung up and when I drug the trailer off an exit from a restaurant, it was the tire that pushed out the bumper like this.
I was more surprised than upset. Granted I have done and do plenty of steel work, so the repair isn't daunting but just creates more work.
My game plan is to relocate the spare tire a little further up, repair/straighten the rear bumper and then reinforce it with more steel to make stronger, then add 4 steel skid wheels to the reinforced bumper to avoid dragging anymore.
I just wanted to point out to any 351-THSS owners that from the rear tires to the end of the trailer is very long and low and will drag easily on steep entrances or exits.