Your reasoning is unsound and as far as journalism goes, dangerous. A pattern of behavior overall does not in itself corroborate a specific instance. In fact, perhaps the perceived pattern was built up out of a series of uncorroborated and potentially false instances. In which case a false stereotype is formed and perpetuated. Even wars have been justified on that basis.

The correct way to report on such matters is to write that the woman "alleges" abuse, or "says" she was abused. If the writer wishes he can add that similar allegations have been made in the past. But do not report as fact something that for which there is no corroboration. That is basic journalism.