This feels like a conversation where it would have been useful for the participants to be very explicit about the points they were trying to convey: the reviewer could have said "Isn't this a quadratic algorithm, because each call to `+=` reallocates `escaped_file_path`?" (or whatever their specific concern was; I may have misunderstood), and the author's initial response could have been "No, because the capacity of the string is doubled when necessary."
