Mall zombies and the process of reanimation

Was at the mall yesterday, and I'm wondering if, at least at this time of year, Romero's vision in Dawn does not apply so much to the zombies when they're wandering aimlessly, but when they're ravenously attacking. At least, that's more what the shoppers looked like yesterday in the Poughkeepsie Galleria. I'm glad it was a short visit, and hopefully the last this season.

Someone asked me about whether all dead bodies will reanimate, or just those who have been bitten. I answered that this was a difference in some of the newer movies, but Romero has continued the tradition of universal reanimation for all dead, non-decayed flesh, still attached to a (semi-)functioning brain. In my fiction, I had actually played around with trying to offer a "logical" or "scientific" explanation for this (that there was an airborne version of the zombie virus that everyone was infected with, and this airborne strain was not deadly, but did cause reanimation), but as I put it on the page, I just didn't see the narrative payoff. In other words, it was a long speech by a scientist to explain a plot device that really didn't need explaining, and wouldn't affect how the characters acted. (I had thought to have it be the device whereby one character would be immune to zombie bites, but as I already had one character who was immune because of exposure to another strain, it was redundant.)