"Look, I don't mean to be dramatic, but I've been stalked before. Multiple times." Claire decided it was only fair to give him some context for her reaction. She had also been murdered more than once, but she wasn't about to bring that up. "So forgive me if I don't find the whole 'I didn't mean to be following you' schtick endearing."
For all she knew he could be some kind of agent playing dumb while undercover to tail her. Maybe it wasn't the most logical guess to jump to for most people, but in her life it really wasn't too far away from ordinary.
"You seem nice, sure, but I don't know if I can really trust you."