He didn't literally hide behind his daughter and peak out from between her legs. I'm sure he would have, given the opportunity.
She answered the door. On the other side of the door, her father and the police with their warrant. Her father refused to provide the code to open the door, preferring the cops to kick the door down and enter the house. Some folks consider that to be an unpleasant and potentially traumatic experience for the kids inside, one that could have been avoided if Balldo wasn't a contemptible creature unwilling to face the consequences of his actions.