Currently playing a Sorc and opened the Necromancy of Thay. I used my Sorc options to expose the book and calm the magic, but didn't learn any spells from it. When having the artifact conversation with Gale, he says I already have an artifact he can use. The Necromancy of Thay is the only artifact I have but it isn't an option to give to him. So either calming the magic makes it useless to Gale and the dialogue incorrectly triggered or it is still useful to him and is missing as an option to give.
I think it is the case that you can’t give Gale the book if you’ve read it. Did you not get the ability to cast Speak with Dead from reading it?
Even if so, it does sound as though there’s a bug with the Gale dialogue. Possibly the flag is set when we get the book but the game doesn’t properly handle the fact it becomes unusable for him. In fact, I’m not sure how it manages other items if you get them and then get rid of them before handing them over. I’ve played this game so many times and there’s still so much I haven’t tried!
