As the DM of this particular group, I must applaud both their resourcefulness and their ingenuity. I let them remain Neutral because...well, they're simply not competent enough to have done anything of REAL merit, good or evil.
IF, however, they plan on, say, butchering the bodies and selling the meat to the less than unsuspecting public, they would find themselves on the quick decent to evil. On top of this, the adventure path doesn't specify that the party must be good, just against the powers that be and such, so them being horrific in the methods they choose to accomplish change is meaningless.
At least thats what I'M telling them.