This really only came to me in a brainstorm last night, but it's something I've been thinking of for a while now, too; especially given the general irritation with the way Harry's conflicts with Snape and Draco were both finally dealt with in Deathly Hallows. For a while, I have felt that JKR didn't give a lot of depth to Harry's character when she never really allowed him to be wrong about a person (or yeah, persons), when there is a conflict. And that's a limitation. But then I do remember that there have been several conflict-resolution situations in Harry Potter, ones which have come across as important, and have more or less been dealt with, if not resolved in the series. But I think the main problem is the way JKR tends to handle this theme when it appears in the books.
(Cut to my journal)