about the end

[Glitch]

Umm, actually Clarance couldn't of been with Philip until sometime after Philip killed Red, because Clarance had infected Red along with some other drones, which is why when he infected you he was confused as to why he was alone.

You show your first sign of infection at the very beginning when crawling past the grate in the first vent (you walk past it, then walk past it again)

Strange though that the virus doesn't know who Red is.