I mentioned the call to my husband and he told me the man must be a storm chaser. According to an old post on Wikipedia's site:
Storm Chaser (contractor): A term used by insurance companies, municipal building departments, local contractors, and the general public to describe roofing and siding contractors from outside a local area that come to help people in need of repair. General contractors do not have enough skilled workers on staff to compensate for such severe damage, so contractors from all over come with a helping hand and their expertise.Apparently these "storm chasers" often times charge very little money but perform terrible jobs and then disappear. The reputable companies have to come in behind them and re-roof the house.
So consider this a buyer beware - if you receive an unsolicited call asking for permission to check your roof, decline the invitation. You can then contact a reputable roofing and siding company in your area to obtain a FREE damage estimate.