I wonder the same thing. BUT... just because these things are written down in a statement does not make them true. She says the older boy witnessed it, but boys that age can be coerced to lie for moms, it happens all the time.
Just like the things he said about her driving drunk with the kids in the car may not be true. Why believe everything the mom says, and not the dad?
Custody battles can be pretty awful, and a feuding couple can do and say some pretty wild things in court, just to make sure they win. Wouldn't be the first time.