Plot hole in canon?

[Bob Schroeck]

Well, IIRC, the Department of Mysteries' entire rack of time turners was explicitly destroyed during the Ministry Battle at the end of Order of the Phoneix, and that was the stockpile of them. So by the time anyone would have thought to use them, they were already gone. I don't think their manufacture was ever explored, but I seem to recall the implication that the supply of something critical to them was also destroyed.