lol... love the sexist remark... it's good value... You're probably more than likely right though, that most men don't make school lunches, but plenty enough do.
My mum went back to work once my youngest sister started school and because she left before my dad did for work, he always did the lunches for us 4 kids. Though I must admit, once we got to High School he got a bit slack and he would many a time give us lunch money saying, 'If you want a home grown lunch, make your own and save the money'.
I think a number of busy working couples these days share household tasks. I've seen quite a number of men do most of the cooking. What I do notice about blokes like that is, (and this is a blanket generalised statement), is that that they won't wash the dishes. They'll do anything but wash those darn dishes. How dare they...
I don't think any of us, (other than people Allison and Gerard may have said something to), know what their agreement was between them when it came to their children and housework when both had some sort of outside work or other commitment. Though, I do see the point you make as to a possible reason as to why he would be making lunches in this case regardless if it was something he did regularly or not.