Way it looked to me the coupler came off the ball but was still held on by the safety chains. Then they had to stop driving it into the tailgate. One of my biggest fears.

You would think the tongue weight would make the tongue fall downwards if it came loose while under way. Maybe a car trailer loading that went horribly wrong??

Every body is thinking about towing a heavy boat , but this person may have had a uhaul or a 200 dollar big box store trailer behind it. And NO towing experience, but it still looks like a dancing trailer tongue to me.

The tailgate down theory mentioned seems most plausible to me.

I will admit that I did something really dumb years ago and ended up with a damaged tailgate. I lived in a house with a VERY steep driveway. I hooked up this old Alumacraft fishing boat to my truck and started down the steep driveway. All of a sudden I felt a bump and heard the crash as the trailer hit the tailgate of the truck. I'm half way down the driveway at this point. Get out of the truck and go back to see that some idiot (me), left the jackstand down when he took off down the driveway. Popped the trailer right off the ball. Cussed a lot, chocked the wheels of the trailer, pulled forward and lowered it down onto the ball and pivoted the jackstand up this time for a change and went fishing. One of the dumber things I've done in my boating/towing career.

I'm half blind but that spot below the handle looked like a hole from a 9mm or .38 that little truck has been on the battle field.

Well, now we're down to 21 of Hillary's top secret emails left, because the confidentiality lid has been blown off this one. Yep, those scrapes were made by Bin Laden's teeth during his fight with a Seal Team 6 operative as Binny's face was being pushed into the tailgate. The dirty bastard. And yes...shots were being fired!!

To many good theories for this not to have happened to most or all of you. I on the the other hand, have no idea how this could have happened...

Customized the back doors of my 2 day old conversion van years Ago with the boat trailer.

Had the parasail boat loaded up with the dinghy on the aft flight deck so there wasn't,t much tongue weight.

To load the trailer at my house the van would hang out and kinda block the street. As I am hitching up the trailer some jakazz loses his mind on the horn and yelling as I am hooking up.

I jump in the van to pull out and clear the street and as I turn wide and the nose of the van dips down into the ditch on the other side of the road I hear a clunk and feel a jerk.

That is when I knew I forgot to lock the coupler down, I accelerated hoping to outrun the chained on trailer but no luck .
It got both doors real good with just 2 blows

I was sooo pissed at the Azzz on the horn.

WOW, Winter does crazy things to people, Still talking about some guys tailgate! and I am still following it. How about he was cutting logs while leaned on the bumper and his chainsaw kicked back

You just crazy in you head. It was clearly parked in a S&M dungeon and that was just where they missed.