I'm betting Hermione is really, really dead (though Harry may yet resurrect her). However, remember that writing a story is often the inverse of reading it. It's like solving a maze by starting from the goal and working backward to the beginning: often much easier.

If (big if) Hermione is resurrected and/or not really dead, then Eliezer very likely started from a narrative goal of having Harry see Hermione's horrible but fake/reversible death and then worked backwards from there to make it happen. As readers we have the much tougher task of working forward from the clues to the correct conclusion.

That is, Eliezer did not have to figure out how to write himself out of this series of events. He constructed these events to lead to the conclusion he wants.