Iason Gabriel comes to mind as a prominent example, but I do think I could find some others too. Maybe Kate Crawford also reasonably fits - she certainly comes from humanities. (This isn't my area, so this is all quite vague to me)

On another note, I don't really buy your analogy to law. AI ethics is inherently interdisciplinary. While I will always be skeptical of people simply coming in with backgrounds from one side or another, I don't think the space should be hostile. After all it requires collaboration.