Someone else might have had doubts, wondered if he'd hit him harder than he'd meant to. Batman didn't. He knew precisely how hard he'd hit. He'd been doing this too many years not to know. It was almost funny, all this indignation over something so small. And then he realized who Schuldig reminded him of when he acted like this and it wasn't funny, not at all.
"I don't know yet." There was Harley, but she wasn't nearly as dangerous on her own, no Joker or Ivy to guide her actions with more purpose. Alone, she was a petty criminal, not a serious threat. The others, he was less sure about, though Batman was suspicious of both Raito and Mikami given their declared crusade. And then there were these recent murders... People here bore watching. Perhaps there was no place for him here, no reason to fight, but he didn't believe that. Though it was possible, of course, that he didn't want to believe it. "I'll have an answer soon enough." Once he'd built a real computer system and spent more time investigating.
Speaking of, "What do you know about these recent murders? Or about someone called Kira?" Not related, but both matters Batman was interested in, both possible threats. He'd been told the danger was over, but he never believed that. In his experience, the best one could hope for was a temporary lull.