User blog comment:IamJakuhoRaikoben/Chapter 467: Mother's Key, Review./@comment-5894890-20160105193600/@comment-1776824-20160106085609

Bar the cuffs, Lucy and Cana were instructed to treat Brandish with care, and not as a prisoner of war. They routinely have to check on her and make sure she's tended to. Obviously Marin's attack and their routine check on Brandish happened to coincide.