I cleared the entire zone. Clearly there are models that look like wood elves, but only a single mob in the entire zone actually gave credit as a wood elf. It's not a bug, rather a lack of attention that all but one of the wood elf models in Torgiran Mines aren't giving credit for slayer seems like a huge oversight. Especially when you consider how very few zones there are that actually give credit for wood elf kills. The very fact a single mob actually gave credit as a wood elf, means in fact, Torgiran Mines does have Wood Elves in it.
Jaggedpine and Greater/Lesser Faydark did it for me. The bandit camp takes a little time but you can just watch TV and get them all.
Timorous Deep, elven outpost. Will most likely give negative faction hits, but I have not tried. If faction does not matter, Kelethin is the place to go. Did mine mostly in Al'Kabor's Nightmare.
I think the slaves can spawn with different races. When I went there for wood elf blood, there was maybe 10 wood elves up. Clear the zone a few times and see what repops. there are also wood elf bandits in gfay too. I assume they don't have bad faction hits