FYI: Version 1 of Ch. 50 had Harry approaching Padma directly... and having to be considerably more threatening in order to have a smaller impact on her, which is what got him in trouble with Hermione in the original version.

Version 2 won out over Version 1 because it was weirder, and therefore more awesome; and also because it got him into less trouble with Hermione - I didn't like having her be quite so clearly in the right in Version 1, i.e., so right that even Harry would notice. It had to end on a note of ambiguity from Harry's perspective.

The thing a reader suggested that I'm embarrassed not to have thought of as an option was that Harry should have gotten a teacher Padma respected to do it. But then Harry would not have thought of this over an even longer time period than I didn't. And it probably still wouldn't have worked as well as the ghost, on a purely individual level for Padma, simply because Mysterious Visitations are supposed to be Life-Changing Events and having a teacher talk to you isn't.