Water has seeped through one of my square heat vents on my roof causing water damage to my kitchen ceiling. This vent is located directly above the damage. The roof is two years old. The roofer is not claiming responsibility stating that the damage occured from "blowing sideways rain" that entered the vent. The roofer came out and inspected the damage and proceeded to strip away about 1/4 inch of shingle around the vent and then chalked the vent edge. Is the water damaged caused by "sideways blowing rain" or the initial improper installation of the roof heat vents.