I don't know if I believe the cut/scratch thing either but I have noticed on the show that if they slow down and point out something directly it's probably for a reason. I don't remember the all infected and turn when dead part I will have to re watch season 1 again. I think some interesting stuff is approaching.
That wasn't actually mentioned in Season 1. It's a potential spoiler from the comic. The only part of Season 1 where that might have been said is when the Dr. whispered in Rick's ear at the CDC, but nobody knows for sure what he said. That's been my guess as to what he said, though.