When will we stop these kind of petty issues??
I would leave it to the parents to decide who should take care of their kids. Simply because a father takes care of his kids, you should not raise a hue/cry over that. Some fathers are better in taking care of kids publicly (mainly in disciplining) than mothers. Give the mothers a break!!
You do not say whether the mother of that child is there or not. If the mother is not present, then the father has to take care of their kids, without choice. Regarding why mother is not there, it could be sickness, it could be job(issue covered elsewhere) or some other inconvenience.
If the father is forced to stand on the podium with the kids, then thats a different issue. Then I would say that the parents have to find some other way to manage their kids for those special occasions where the father has to take a special role in the meeting. And instead of saying, why cant the mother take care of the kids, I would ask - Why does the father want to lead the congregation if he cannot find suitable arrangement for taking care of his kids?
However, if the kids are quiet and not making much disturbance and the father is forced to lead (for lack of other suitable leaders), there is no need to get provoked.