Someone needs to call the police.
George realized he needed help when Rex sprang at the door howling and growling. Calling the police felt like the safest decision, given that the menacing guy had shown up looking for Zoey. Involvement from the police in whatever had been happening behind Zoey’s back may be the last push she needed to come clean. At the same time, the police presence would unnerve the odd guy and cause him to flee.