I think it's Lori, I had to watch the last episode on my computer and the definition sucks but I didn't see loris body just blood and the walker with a full belly.
The external phone lines would work but the internal system should as long as there is power.
That's what I was thinking they must have buried her right, 3 graves?
But they never said how she died, maybe it's carol on the phone
Another thing they have seemed to over looked. It's doubtful that zombie would have ate Lori's entire body and was able to squeeze into his basketball sized belly. What about bones? AND they are playing it up that she's dead too much (even on talking dead) which makes me suspicious.
So that's more on why she might still be alive, but prolly she IS dead.
From what i understand the phone and the potential ensuing conversation might be Rick going nuts.
Carol calling seems like the most likely explanation.
Some further thoughts:
- They should be clearing out the rest of the walkers in the prison.
- Knowing from season one that they can mask their scent with walker flesh they should surround the outer fence with armless, jawless walkers tied to it.