That is a good question but i'm guessing the zombies was there just for effect. Was this in season 3?
DeNiro, part was season two. She sort started watching somewhere in the middle Sunday when they were replaying episodes. My thought was that even tho everyone has the infection, NOT everyone turns. Don't know my Zombie history. LOL

TIS
It's funny cause Sunday AMC ran WD all day. She watched when she could (not letting her 3 small kids see it) and she'd call and ask a question. It took me a couple minutes to figure out she wasn't watching the same episode as I was. She was a few ahead. No wonder I didn't know what she was talking about.

She has direct tv and I have Time Warner is the only reason I can think of as far as the sequence goes.