Sorry to hear about your mishap, but glad there wasn't any major damage. Bumping down the road at XX mph can shake a lot of things loose - including the kitchen sink! In my first TT, the factory installer had cut the drop tube out of the sink so short that it didn't take much to shake it loose. I'd do the dishes at night (before going to bed), and in the morning there would be water on the floor. Took me three or four outings to figure out that's where it was coming from. Fortunately, the CG was close to a Home Depot, and I was able to pick up a longer drop tube and get it installed. Also fortunate, I took along my little tool kit.
Your advise to check your S-trap connection each time you pull into the campground is very sound. Thanks for reminding us! And always carry a few tools: including a hammer, some screw drivers, pliers, a couple of wrenches and/or channel locks, a small hack saw, a utility knife, and (of coarse) the handyman's helper - duct tape.