Pilar's curse has expressed some skeptical sentiments along the lines of, they really should not expect that much active help from Chaotic Good about some nefarious plans. It's not going to act against Asmodeus's interests, but there are some places where it seems less Chaotic Good to actively help out than others.
So she's standing just outside the Alarm radius, and moving forwards even as Keltham speaks; her curse is apparently at least willing to cooperate with not showing Keltham that Pilar's curse doesn't work like that around Alarm spells.
Pilar knocks gently on the door. "Cake delivery," she calls. Keltham said out loud that he wanted chocolate, but he was thinking about cake.