At the end of the previous section, Beatty is on a tirade directed at Montag when he is interrupted by the fire alarm. When it turns out the targeted home is Montag's, two sides of Beatty clearly come through. First, Beatty seems regretful of what he must do. He seems torn between duty and a sense of conscience (possibly driven by his relationship with Montag). This is made most clear when he says:
Old Montag wanted to fly near the sun and now that he's burnt his damn wings, he wonders why. Didn't I hint enough when I sent the Hound around to your place?
This shows that Beatty has likely known of Montag's secret all along, but somehow wanted to give Montag a chance to make the right choice. In the end however, Beatty reveals pure malice when he makes Montag torch his own house.
A duplicity of Beatty's character is shown in this final section of the novel. While he is meant to represent the voice which rationalizes this utopian society, it is clear that he is also still human.