@Esasaeriri it's more likely that Christopher did off-himself. the faces seem to be strongly personified with loyalty, and I doubt the author would bring up an exception at this time when it should be reinforced that the two bound and working together. the exception could possible be our resident blonde. otherwise it was explicitly mentioned that Christopher was lacking in confidence and how the face worked behind the scenes. Christoper obviously appreciated Anthony's existence, and I could assume he could never be able to take away Anthony's life.
I adore the exposition in this chapter. but one thing that is an important clue in this mass-release, children use to personally regulate the coffee. the celebration of happiness seems to be something the adults asked the children's building to enforce. so it is possible that Anthony, because of how much of a charismatic enigma he is, to manipulate his shadow to take his life- but I think it would be unlikely
(it's probably not the end of this flashback. it'll probably flip between the questioning and the flashback, as well as Kate's perspective, because they still have explained why the method of delivering coffee has changed. it could be that Anthony did do something, resulting in "dissidents" being named. Rosemary could be blaming herself because she cared for both- Anthony and Christopher, but that resulted in both of them being annihilated)