At her feigned guilt, he simply crossed his arms and looked at her. Only Selina would see that there was something wrong with admitting to doing something decent when there was nothing to be gained by lying. Batman turned to look away from her for a moment.
"I was in the neighborhood. There's been a few problems in the past couple of days>" He was absolutely not going to tell her he was worried about what Joker, or the sidekicks from the future might have tried. He had no way of knowing what she would mean to him in those days.
"I had to make sure you weren't going to be causing trouble."