As far as Maeve's comment, I could also see that as similar to the mirrors in Molly's soulgaze. Not really a sign that a grandmaster strategist is making a move, but a nice easter egg for us to look back upon. Maeve was right, but she had no idea how right she was.
The timeline for Justine's infection is an interesting one. Nemesis says it was ever since Justine had become close to Lara, but that might not be reliable. Justine saving a child from the Fomor in the Marcone short story muddies the water for motivations there as well. As an Important Story EventTM, Justine getting Nemfected probably happened in the background of one of the main books where some kind of throwaway line is a clue. CD is an obvious candidate, but are there earlier possibilities?