Might be a good way to get a stalled car off the road quicker than a tow truck can get there. I wouldn't want to do a long tow as shown in the video.
I would be willing to bet that there are brakes on that trailer..murder on clutches .... and the most important aspect .... "stopping "????? should be under towing things wrong .....
I've seen similar video of these devices used in Asia (Japan perhaps) Seems expedient.