I say that such people have true liberation. Ahimsa refers to the compassionate, non-violent treatment of animals and all sentient beings. One also hurts one's self since all beings are a part of one whole. One also spreads the bad killing karma, which will later cause one suffering, or propagate more killing. One also enforces the suffering caused by the cycle of death and rebirth.
All sentient beings desire to live.
So to the Buddhist, a butcher is the worst trade. However, as a consumer, purposefully buying or consuming animals is a part of the killing process. By creating demand, it is the same as killing the sentient beings yourself. When a sentient being dies, it is forced to begin again the painful process of rebirth. The only way to stop this cycle is to reach full enlightenment.