For argument's sake, let's say Eugene is right and the odd behaviour means the walkers are indeed evolving. This goes against the storyline of the comics, but at this point, I think it's safe to say no one's really concerned about that anymore. Evolving walkers would raise the danger for our survivors tenfold, to a degree that I'm not sure I even want to explore. Imagine someone trying to fight a walker with an actual personality?! The stress! Honestly, if the show does go down this route, there's a chance I could respect such a ballsy departure from canon. But it better not, because it makes no sense and we have been through enough, thank you very much.