I would guess the bucket must not have been dropped to the deck and the hydraulics must have been somehow inactive?

When I hauled backhoes, I would put the bucket on the trailer deck and put a chain across it. Just to prevent that from happening. Never trust the hydraulics to hold anything. I have never seen a backhoe with a pin to keep the boom from moving.

hmmm... I think Dad's backhoe has a travel pin but I don't think it prevents that. It seems like a simple safety feature to add.

I'm speculating here, and getting a little outside of my knowledge, but that won't prevent me from spouting off. I think built up pressure in the hydraulic hoses tend to keep the shovel in position. If a hose is leaking, the pressure will drop, and the shovel can move then. Maybe a hose or fitting was leaking.

You never trust the hydraulics to hold in transit.

If I personally owned the truck in UT's post, I don't think I need a CDL in KY to drive that truck. As I say, I am frequently wrong.

I did not need a CDL to drive my bucket truck, but, it was a single axle.

Bruce, it's actually 26,001 and over GVW and certain combinations.

Dah rulez

Thanks, I gave up my CDL when they required testing.

What, like brakes?

He won't talk his way out of this one...

Asshole. I cannot muster enough "whatever" to care that its a problem anymore.
Drunk fuckers destroy families and lives.

Drunk ƒuckers create families and additional lives.:p:

Drunk drivers, though, agreed.

That was an extremely accommodating officer/Trooper/whatever. Courteous, even.

I have no words. What a discredit to our profession.