When Shane was face-to-face with Randall in the shed, it seemed quite intentional the way they showed the cuts on Randall's wrists from the cuffs, and the almost epiphany-like, wheels-in-motion, of Shane's thought process.<div>
</div><div>Now, flash back to a few episodes ago--the two dead officers. Rick stated that if you looked closely you could see scratches on their faces. This foreshadowed his struggle later in the episode when he was pinned down by a dead walker and the other zombie was close to scratching him. They also conveniently started using their knifes in this episode to kill walkers.</div><div>
</div><div>So--I know this isn't as sexy as a "everyone is a carrier" theory, but could Shane have simply wiped his knife blade (or found some other walker blood) on Randall's wrists? And then when Rick killed Shane w/ his knife--could it not have been that Rick's knife was simply contaminated?</div><div>
</div><div>If I'm missing something here please fill me in. But this just seems too logical to me to ignore.</div>