As far as we know the father hasn't done anything. But, he must have been suspicious of something because he called the day care to check on the baby. Maybe he was checking if the mother had taken the baby there. He was unfortunately negligent for leaving a depressed and delusional woman alone with the baby. I do not think that he meant any harm to any of the children. But, if he knew his wife was a threat to the children, he should have done something.
But wait, wasn't he assured by the experts after a 7 month investigation that every thing was o.k.?