When Wesley translated the page, it said "the father will kill the son." But then he went to the talking Hamburger, who said "That the vampire will devour his child is certain." This came true when Lilah arranged to have Connor's blood put into Angel usual blood supply.
Also, that prophecy was "created" by Sahjahn to stop the prophecy that COnnor would grow up and kill him. Which also happened, and was able to happen because he had been sent to Qur'toth.

That's what JKR was talking about when she asked whether Voldemort would have gone after Harry, if there would have been a Boy-Who-Lived if Voldemort hadn't heard the prophecy. And that that prophecy really only describes a situation, it doesn't describe anything mystical or hidden.