Driver went full retard.
Never go full retard.
**Did not look like a elevated grade crossing that could have high centered the trailer landing gear…**
I don’t have X, so I haven’t watched the video. Was the trailer a lowboy or de-tatch, or a stepdeck (flat or enclosed). Doesn’t take much to high center those.
Also, some combination rig ‘drivers’ are too lazy to crank the landing gear up very far. In those cases, with very slow speeds (10-20 mph), the gear can stop the truck; especially one with little or no load.