Extreme silliness, if you ask me. A great way to wreck good equipment. Definitely not to be attempted without at least one reserve vehicle (which they did have) to bail out the main rig.
Looking at how they bottomed the tongue out several times reminded me of the time when, as a teenager, I got a big John Deere 4230 tractor stuck by pulling a disk straight across a small ditch. The rear tires
were at the bottom and the disk tongue was hung up on the top. Dad had to dig with a shovel to get the hitch pin pulled out, pull the tractor out & around, yank the disk backward with a chain, and then we hooked up again. I was so embarrassed. There's no way I'd take chances like those with my travel trailer.