Nor does it explain the pain in Harry's scar or his crawling feeling after the gunshots. (Harry was supposedly never under the curse to begin with, in which case he can't still be under it.)

Relevant, from Ch 111:

Harry felt a sense of terrifying apprehension in the air, as though the sense of doom had always been been out of focus and had now clarified, concentrated into a physical pain in the scar on Harry's forehead.