They say the trailer doesn't have any cargo in it. They also have freshwater in it, and as I just found out, the tank is behind the rear axle so I'd say that would take more weight off the tongue than cargo would? Since almost all the cargo areas are over or in front of the axles. They don't specify if they weighed with a battery and the spare tire, but I'd think they would have?
Our tongue weight was after a fully packed trip. We weighed at the truck scale near our house. I just went and checked my notes and the numbers we got were:
Trailer - 2010 kg = 4430 pounds (hooked up to truck so no tongue in this weight)
Tongue 340 kg = 749 pounds WDH would likely have been sitting on the scale with it and I believe our WDH is 50-60 pounds (the Andersen so it's light).
We did also weigh prior to being fully packed for camping, at home on a bathroom scale that maxes at 550#. With only battery, tongue jack (NO propane), the tongue was around 518#. Right around 550# with one tank of propane.
I can hope that the scale was grossly miscalibrated and that when we weigh it in a few weeks I get different numbers. Or maybe the scale just has a high variance at lower weights. It's not a scale that's manned. It's just on the side of the road so I don't know its status as to how often it's maintained or calibrated.