I know it's a totally different type of story, different rhythm and timing, but the ending sort of reminded me of those stories where the babysitter is on the phone downstairs and the cop calls and says, "get out, the killer is in the house!"
In this case, the cop was the mother, and instead of being urgent about it, she almost nonchalantly tells the guy, "oh. by the way. You ate your kid."
As said above, a Dickensian story of loss and then boom! in your face! you ate your kid.
I don't know why I get that babysitter story feel from this. Because there doesn't seem to be any great alarm from the mother. More along the lines of, oh well, that's what happens out at sea.