The Latin term vaticinium ex eventu is used by liberal scholars and critics of the Bible to describe a prophecy they believe was made “from the event”, or literally after the fact. For example, German scholar Ferdinand Hitzig objected to prophecies about the king of Egypt made in Jeremiah 44:29-30, calling them vaticinium ex eventu. The argument of men like Hitzig is that later writers forged one or more prophecies in Jeremiah’s name based on events which had already occurred, and grafted them into the existing text of Jeremiah, presumably in order to make his writings appear more credible.
Hitzig died in 1875, by the way, so obviously this is not a new issue. And he’s far from the only expert to make such claims.