...perhaps he shouldn't be left alone to watch a child?

BTW, does his medical condition not allow him to take positive steps to insure that a toddler can't get out of the house?

After the very first sleepwalking incident involving her son, an old girlfriend had me install security chains well above the child's reach on both doors. She was caught by surprise when he walked right past her one night, and she followed him as he opened the front door and walked around in the yard while sound asleep.

This guy, however, already knew about his problems and he's lucky his daughter didn't die because of his carelessness.