Ash isn’t a Zombie, why?
Well... if I’m honest, I watched the scene over and over again to think of logic to it. This isn’t a perfect answer but still, so after consulting a ‘Pirates Express’ episode which involves medusa turning some one to stone they went to get a cure for it. The cure for this was tears which brought him back to life. He was revived. So, logically he is either immortal or his friends always bring him back to life.