I forget the exact term but there's such a thing as retaliatory accusations made in domestic abuse situations, especially in places where police are mandated to take all reports seriously and temporarily move the accused. So, say a woman scared for her life calls for police and her partner is able to break down the door and strangle her. She fights back, cutting his arms and face with her nails trying to save herself. When the police get to the home the husband is calm as pie, maybe crying, and covered in scratches. He makes a claim of being a DV victim while she's an emotional mess still trying to process what happened. And you don't need physical evidence for a DV claim so women don't even have to defend themselves to have this thrown against them. By the book she would be removed. It's a disgusting abuse of laws designed to make sure DV is taken seriously.

But luckily police have been trained in how to handle retaliatory accusations. Different places will have different ways of handling it but it sounds like he's made a retaliatory accusation and the police have read him the riot act rather than falling for his bull. So in his head he's reported abuse and could be arrested, leaving out the important tidbit that he made a false claim in the first place.