The book I have is definitely for more than one model. When I am around my camper again I will grab the axle info and call the company direct to see what they recommend for torque. I have a good torque wrench but I can borrow my brothers and see if they line up. So I did torque the nuts before I left the dealership and I can say that non of the nuts moved before I got to 120 ft-lbf. I then rechecked them that same day when I got home - about a 60 mile drive. I checked them again when I got it out of storage so about another 100 miles later. Non of the times that I checked did any of the nuts move. So my guess is they were spun on with an impact at the factory and are probably above the 120 ft-lb mark. This spring I will take all of the tires off and see if there is any necking of the lugs and then put the wheels and torque properly.
The reason for starting the thread was to see if anybody else had experienced this. So far it sounds like this is a fluke. So long as everything is torqued properly I shouldn't have to worry about another tire flying off.
Funny side story. So there I was sitting on the side of a road with a spare tire but no lugs. I luckily found a Napa that was open and found lugs that were close to the right size. I drove the sheared lugs out and pressed the new ones in at shop in town. Went back and limped the camper home. When I called the warranty department their statement to me was "you shouldn't have fixed it". What was I supposed to do, leave it on the side of the road. I couldn't tow it because this style of walking leaf springs allowed the remaining tire on that side to rub on the bottom of my camper.