Teeter totter, that is what you could have with no weight on the tongue, and no stabilization in the rear.
While we were working on Vintage Thunder Rich and I had just such a scare. The entire front of the trailer was empty and we had it attached to his TV. BUT we only had a 2 inch ball since the new hitch had not come. We were not towing it more than 100 yards.
We backed the trailer up on car ramps and left it attached to the TV to hold it there. This way we could work under the rear and have some room. Chocked the wheels (good thing as it turned out) and got to work.
At some point in the day Rich was inside in the bathroom working on one of the many projects and had a question. I pulled myself out from under the trailer and went in to see what he was asking about. About the time we both got to the bathroom the tongue of the trailer decided to LIFT OFF THE BALL!!!
We looked at each other with an OH S**T and I ran toward the front. The weight transfer dropped the trailer back down on the ball. There was no damage to the trailer or the TV because we chocked it so it could not ROLL OFF THE RAMPS!!!!
In the end all we got out of it was an adrenaline rush. From then on we stacked 4 concrete blocks on the A-Frame any time we were on the ramps.