Even if the target set his computer to auto-update (or something that did not require admin authentication), wouldn't he have some type of notion that something went wrong during his update?
With the target being an InfoSec guy, I would've imagined he would at least be running some type of network monitoring, like wireshark or little snitch, ESP on his personal computer. Wouldn't he have to authorize the outgoing packets?
Sorry, if I come off analytical to the story...it's a great read...I just want to make sure my networks are locked down. I've even went as far as dedicated networks for my server and home usage, and preventing internal ip addresses from communicating to each other (sucks for airplay).