Do the children need to respect their father who provoked their mother to commit suicide?

A couple was in the habit of having constant conjugal fights. In the course of one such altercation, the husband asked the wife, "Can't you get any poison?". The wife then and there got the insecticide which was incidentally at their house, drank it, and in-spite-of the best efforts from the doctors, died in hospital after fighting with death for two days. Now, definitely, the woman is in a very big sin by committing suicide. On the other hand, the question is, the children of this fellow want to know how should they treat their father in light of Islamic teachings? He is their father non-the-less. Again, he is the person who is indirectly responsible for the act committed by their mother.