In Order of the Phoenix, Harry can see Thestrals, because he saw… - Sally's Journal — LiveJournal
|Date:||December 8th, 2005 01:22 pm (UTC)|| |
He didn't really see it, so it doesn't count.
I don't think it was a mistake so much as "Argh, this doesn't really work, but I can't do it another way without messing up the plot so I'd better come up with reasons to explain it." And there are holes right and left in the HP world; I love the books, but they're not greatly written. C'est la vie.