Sounds like a religion. I get not wanting factory farmed meat, but what's wrong with hunting meat for yourself? In the end we're all meat for something, even if it's just the worms.
I believe the argument is that if you were capable of subsisting without harming another living creature, then you should try to do that.
My understanding is that it's an ethical decision about not killing an animal (or some animals) or directly supporting the killing of an animal. Hunting would be in conflict with this decision. The consequences around an animal's killing are irrelevant here.
It then seems that if an animal is dead, and you are simply picking up small traces from a grill, vegans ought not to have an issue.