I think that's more for gameplay purposes only. In the cut scene for Cotd, they weren't really trying to slap the celebrities as it certainly looked like they were trying to take a bite out of them.
And does anyone find it weird that they specifically went for George Romero like that? I'm sure the zombies only attacked them in the first place because of the original crew's presence there, but it's all so very weird.
Maybe, the zombies could somehow sense that they alone couldn't get to the Original Crew on their own, so they took the most advanced mind in the area, (George) and somehow turned him into a zombie. But, he went after the celebs, for reasons unknown, maybe because they were in the way, instead of the Original Crew.
Think about it!
i believe that samantha did kill george because she mistook him as a member of group 935 when he found the 115, but since the actors were helping the crew continue the story, she knew she would have to try and stop them.