Advocating for the devil here, but is this lock and chain comically large and heavy? Something like that is bound to draw comments or questions. And if the purpose of said lock and chain is to simply keep honest people honest, would it necessarily need to be very large? Obviously, it’s not practical to swap through several different locks in an attempt to match the lock to the situation, but to a non cyclist a comically large lock and chain applied for a simple in-and-out quick stop might appear laughable. Such an incongruity might trigger unsolicited comments.
Were it me, I probably would have smiled and refrained from responding to the comment.
-Kedosto