A case of a person who is eating non-sacred food at the level of purity of sacrificial food - which doesn't really give off that impurity to the next level. Plus, the hierarchy of impurity means that something that is pure in and of itself can be regarded as impure in comparison to something that is pure with a higher standard of purity. Also, on the susceptibility of impurity - will shechitah itself render the meat susceptible to impurity? Plus, the impact of how an animal dies, including whether at the hands of the Angel of Death. That is, the blood of the animal should establish susceptibility to impurity -- regardless of how the animal died.