Piecar had mentioned this in his post, and I thought the exact same thing. Dale should have seen that crowd of zombies coming from a mile away. Especially on top of the RV. Extremely poor writing like this is what ruins a very good show. Pretty soon there's going to be more scenes like this that aren't caught. Oh, one last thing...Piecar, they didn't pass those zombies. They were looking ahead off into the distance of where they were going. The RV is facing forwards still.
Please writers of The Walking Dead, stop making these huge mistakes. I know it's a zombie show, but it's meant to seem realistic, right? So, next time don't write a scene where a man with binoculars, standing approximately 15 or so feet above the road, can't see a crowd of at LEAST 200 zombies approaching his way. When he finally DOES see them, they are freaking 20 or so feet from the RV. It was such an obvious error. And something that just should have been caught.