It's true, as the Court of Appeal mentions, that there's no specific evidence that Father has ever driven drunk while four of his six children were in the car. Or that Mother knew that Father was driving drunk with those four children in the vehicle. For that reason, the Court of Appeal holds that it was improper for the trial court to exercise dependency jurisdiction over those four children.
But Father was twice arrested for driving drunk with the other two children in the vehicle. And Mother let him; indeed, she once let him drive drunk with the kids the very next day after she told the social worker that Father shouldn't drive drunk with the kids.
It's also not like this is an isolated incidence. Father has been arrested for drunk driving not once, not twice, not three times, but . . . twelve times.
Doesn't it seem reasonable to conclude that someone who's been arrested for drunk driving twelve times, included repeated occasions in which his kids were in the vehicle at the time, might again drive drunk with children in the vehicle? Including but not limited to the kids he's not yet been caught driving drunk with?