As for Law, he'd vote for Alistair's research / anything to do with the World Eaters, as they're their main concern right now.

He's against dumping the body anywhere in water because contamination, hello, if it causes people to feel ill by being nearby then what will it do when it contaminates all of the water... so no. He's not against anyone trying to burn it, though the fumes would have to be contained somehow for that — mostly, he's thinking if he could just find a room no one uses and teleport the carcass into that room and just close the door and never open it again.

Or something.