Ok, lets just say for chits and giggles I weigh..aaa..lets say 260. With the camper suported on the same structure as if it was in the bed of the truck not secured ,if there were 260lbs in the master ...
Here's a fairly easy way to tell if the camper is in the truck. Unhook or loosen the tie-downs. Have someone stand outside of the camper and watch while you get up in the front of the camper and bounce around - put two or three of you up there.
The person watching can tell if the rear of the camper is coming up off of the bed of the truck. The most it can tilt is a couple of inches because the roof of the truck is right there below the bed.