Vaughn, I did the same thing last year. Was helping a friend with his septic and water lines on a new lot at Hot Springs, Ark. last summer. One evening, in a hurry, working by myself, it's a 110 deg. or so and I drop the ramps on the old Belshe three axel back hoe trailer that I've converted from a pintel hitch to a gooseneck.
The truck and trailer are on the street on a pretty good hill, at days end, I run the hoe up on the ramps, get the front wheels on the trailer and the whole rig starts down the hill backwards.
I get big eyed,,,,,,,, torn between jumping off or backing the hoe up. Well after a complete and careful evulation of the options for about Oh, a 1/2 second, I see it's all headed for a big empty yard.
After rolling about 20 yards, the whole kit-n-kabotle comes safetly to a stop. Moments later the neighbors called 911 and the local response team used The Jaws of Life to help me out of the seat.
I now carry and use chock blocks when hooked to any trailer.