I was a fan of the first Resident Evil, but after discovery of what was going on, the series kind of went downhill for me. What made it so enthralling was the fact that you were a few ragtag cops in an undisclosed mansion full of who knows what lurking around every corner, and to make it worse, you had lost all communication with the outside world. There is just something about the suspense of a survival game, especially if you have no idea where you are or what is going on, that makes it exciting. As the series progressed, or should I say digressed, they added more and more complexity into the mix to keep it interesting, but ended up making it ridiculously over-the-top.

Getting back to the question at hand, I think any being that is undead or has lost what makes it unique can be considered a zombie, although in a different sense. You could be an undead zombie, or a zombie of the laws of a government, or maybe even an undead government-abiding zombie. Considering that most zombies still have motor-skills (and to some extent, a brain), it would be safe to assume that zombies could indeed mutate or evolve into something entirely different, and possibly even adapt to using tools. So, I do believe it possible that they could do these things and still be considered zombies.

But just remember, zombie-like or not, if it wants to eat your brains, I think it's safe to say you should kill it.