Everything was thawed completely but the skull. It felt slightly hard but I thought it was just because the mouse was a medium mouse and not a fuzzies. Also when I squeezed it slightly it stared bleeding so i just thought that it was thawed and just hard bones.
And yeah he he didn't get it down but he did tear it open and make a mess. He didn't swoops any part of the head though, I closely checked the mouse and it seems he just tore it.
Thanks for the reply. I'll definitely keep an eye on him and stick to thawing overnight in the fridge.