Looks like the female officer, who looks like his sister, is now nothing but a loose end for the MC. She's working for the enemy in practice, willingly or unwillingly. A good thing is that the hospital can't really hide itself, so it's a sitting duck target for him. The same goes for that so called "defence force". If they want to make an enemy out of him, he might as well give them what they want. In a certain sense the defence force did a favour for the MC by not arranging a trap for him, using the female cop, but instead posted this giant warning, telling him to stay out of sight.