Sounds like they
goofed up the first time. which now, any damage after the repairs would be on them. I would be concerned about rotting and structural damage, but if they say they got it, then there is not much you can do, but in the future where there is damage cased by leaking water, I would refer back to this, and their comment on making the issue worse due to not using the correct caulk the first time.
My experience with dealers are not good. If I have the ability (Money), I would open an RV repair shop with better customer service and better trained technicians than most that are out there now. They are hard to come by!