I investigated a similar wreck a couple years ago. F350 dually pulling a tracked loader on a heavy duty trailer. Plenty of truck and plenty of trailer for that loader. The guy has owned that combo for years and towed it thousands of times. This time he was in a hurry and placed the loader a little further back on the trailer than he normally does. That caused too little tongue weight and driving up the road the back end got loose. The F350 dually went from the right lane to the left, back to the right shoulder before the truck flipped over and was pushed back to the left median.
Just goes to show that even with the right tow rig and trailer, mistakes can still be made. If he was pulling that trailer with a F150 and sufficient tongue weight, it wouldn't have wrecked and flipped. It woulda driven like hell and likely caused some long term damage though.