What I want to know, is the mortals cannot be infected bit purely a theory stated here by us that said long enough and hard enough believed to be absolutely true? Or is there a WOJ out there that states that and either Jim out right lied to us or changed his mind on the subject? Or did he just sing, "I ain't a going to tell you..." And we just ran with it believing what we wanted to believe? 
The theory always went like this:
Premise 1: Nemesis gives the infected Choice/the ability to act against their nature.
Premise 2: Mortals have Choice/the ability to act against their nature.
Conclusion: Nemesis can't infect mortals.
That logic was always shaky and Premise 1 was always a misstatement. It should have been "Nemesis gives fairies Choice/the ability to act against their nature."
The conclusion was usually hotly contested.
Another possibility, just as simple and unique to Justine, she suffered from mental illness to begin with, suggesting that she might have been infected from the get go.
Or perhaps Nemesis allowed Justine to change her nature from insane to sane. Chalking her improvement up to "medicine" always seemed a bit off to me and others here.
In fact, when Cold Days came out and Lily literally stated which mortals had been infected most people said she is probably mistaken. Ridiculous. Even when the author tells you straight up, it's like no one trusts him.... ah well that's his own fault.
Jim did say the first time we saw an infected on screen was
Grave Peril. Lily said Nemesis was behind those cases. Like how Nemesis was behind the Titan, but the Titan wasn't necessarily infected.
Wasn't Nemesis infecting Maeve at the same time as Lea at some point?
That's always been my read. Cat Sith and Maeve were both infected in CD.
I still say that we only know what Nemesis offers fairies. It could work different in every different kind of creature.
