Why is my Sir Lankan Hindu co-worker offended that we killed a lamb?

According to Vedic teachings being a butcher is an unacceptable occupation. Actually, meat eating is prohibited also except under certain circumstances, but this man apparently doesn't follow that. Many Indian persons stop following vegetarianism when they move to a western country, unfortunately. Actually, according to the scriptures, the person who does the killing, the person who transports the meat, the person who sells the meat, and the person who eats the meat,... all are implicated in the bad karma. This co-worker is not following strictly it seems but this was too much for him to deal with, seeing the animal killed. He also was probably taught its okay to eat if you didn't kill it, but that's simply not the original teaching of the Vedas.