This may be correct, keep in mind Iam no expert, I have only had one water damage claim. My wife also worked as claim rep. previously and always told me it is more about what you told them or what not say. I talked to several people with the insurance company while making my claim and they would ask if I new where the water was coming in, my response was there is no leak/water coming, the damage is from parking it on a slant over the winter and the water/snow melt running off in the same places on the one side of the trailer and curling underneath, soaking the insulation under the trailer. They more then likely wont pay for something that is routine maintance, like a leak that develops in the roof(caulking/seam) or an outside light fixture. Iam not sure about your crack above the door, maybe water in the wall that froze?