[NH_Bulldog]

Is he releasing horizontal pressure off the tow vehicle before unhooking? Like get the trailer set and blocked, put tow vehicle in neutral, e-brake off, foot off the brake and see if it moves? If there is still horizontal pressure, forward or back, the trailer will move when it pops off the ball. Someone can get hurt here......

I use a leveling chock similar to the Anderson brand along with a LevelMate Pro. Back onto the leveling chocks, stop when light turns green, insert other half of chocks, give them a good whack with a rubber mallet to seat them and both wheels on one side are cradled. Insert conventional chocks fore and aft of both wheels on the other side that is still on the ground, again whack with a rubber mallet. Truck in park (no e-brake on), raise the tongue jack, move truck forward, set tongue jack until LevelMate light goes green, give all chocks another whack with rubber mallet, install Xtended X Chocks (wide stance axles), drop stabilizer jacks on slide side then door side, and we are good to go.