Ouch !! I've done that twice with GN trailers. Both were in the dark on a wet and muddy worksite. The first one the landing jacks with boards underneath sunk more after checking with a flashlite. Being muddy the tires spun so it only dented the gate.
The second time I forgot to drop the gate and a big rain storm was fixing to hit. I rushed to get unhooked and off the dirt before it turned to mud. This time it pulled the gate completely off the truck.
I put a vented V gate on before making my reload run so the other drivers never knew my goof.