I'm bothered by the fact that Rangiku went on her own to kill Joseki thus causing trouble for Garra and Naruto. However they could make a argument that since Shukaku and the other Biju were taken from the akatsuki by a unkown group it could be this group who killed Joseki and not Garra. It seems that the Diamyo is fully against Garra and isn't willing to give him the benefit of a doubt.