Clecic can block it too and have same description. It happen many times that my CB Rigard block Alfrike mindless attack. The description is usually a bit ambiguous.
In fact, Baldur buff damage isn’t 100% special skill since Glenda can’t boost that damage. I don’t know why but I think it is its own category. Could you test Reuben buff vs mindless attack, Reuben buff vs Gulli and Taunt vs mindless attack ?