The idea that this is possible was strengthened again in this episode. The walkers eating on Justin came very close to being still munching on him when he started moving. Another few seconds and that would have been the case. This isn't the first time we've seen this. Patrick was still gobbling on Greg back in S4 at the prison only seconds before Greg got up as a walker. We've seen people wake up as walkers in less than a minute after dying. And we've seen walkers chomping on victims' bodies longer than that after they were dead. For instance, Merle was still eating the body of one of the Governor's men long after the battle was over.

So, if we put these facts together, its logically possible for a walker to be biting an animated walker. I'd like to see them capitalize on this with some neat visual gags, like a fresh walker crawling along the ground while an old walker chomps at his legs, or one walker following behind a fresh walker in the woods, with the intent to bite. Or maybe TWO fresh walkers who were both living people only a couple minutes earlier, eating EACH OTHER!

 

That would be horrifying if true . It would mean that if ONE walker knew about your safe zone, every walker knew about it lol. Yikes!