I am kinda amused by some of the posts. Have you ever really looked at how your tie-down brackets are installed on your TC.
I think it is fair to ask the question: Are the tie-downs expected to hold the TC to the truck, like a 4,000 pound load on a big truck that uses several straps and possibly chains?
I see a couple of things not really talked about in the posts. Notice the ruts in the road? I think I am looking at a road of sand, hit a rut on one side of the truck, sure looks like that side of the truck would tip quite a bit. Add to that a strong gust of side wind.
Personally, I have seen semis laying on their side, some with their loads still attached, and some not. I am of the belief several things were at play here, and question the TC manufacture could correct them.
I do hope the story has a happy ending. It appears the OP thinks so.
Wayne