It would be called the "ad hoc fallacy"
http://atheism.about.com/library/FAQs/sk..._adhoc.htm
http://atheism.about.com/library/FAQs/sk..._adhoc.htm
Quote:Strictly speaking, an ad hoc fallacy shouldn't really be considered a fallacy because it occurs when a faulty explanation is given for some event rather than as faulty reasoning in an argument. However, such explanations are usually designed to look like arguments, and as such, they need to be addressed - especially here, since they purport to identify causes of events.
