That accusation startles Cal enough that he stops in his tracks, turning back to her with a renewed sense of panic.

"Because I didn't!" Cal has enough presence of mind to keep his voice down, at least. "I'm not involved with those people. I wouldn't do something like that!" He might have a better excuse, sure, but he couldn't tell some random stranger that he doesn't want to be stopped by the police. That would probably just make the whole thing worse.