Whose fault?

The other night Dad had to go downstairs and decided to walk in the dark. He ended up stepping on the edge of Huggy Bear's tail, leaving a clump of Huggy hair in the foyer. So whose fault is it? Is it Huggy Bear's fault for not moving since he has better night vision? Is it Dad's fault for not turning on a light and for having such big feet? Or is it the darkness' fault for being so dark?