Matheny has another article: Expected Utility,
Contributory Causation, and Vegetarianism. It's in the
Journal of Applied Philosophy, and is available in PDF
at http://www.veganoutreach.org/spam/thresholds.pdf
(requires the Adobe Acrobat reader).

The task he has set himself is to take apart the
occasionally encountered omnivore's argument that a) he
doesn't personally kill the animals he eats, and b) his
meat consumption doesn't bring about the whole meat
industry, so "he" cannot be held accountable. Matheny
attempts to show that all meat eaters together are in
fact accountable for all the deaths of animals they
eat, based on expected utility considerations.

His analysis is fair enough, and I don't have a problem
with it as far as it goes. What is curious, however,
is that it also links vegetarians to the collateral
deaths caused by the production of the crops they eat.
This in fact is straightforward: neither meat eaters
nor vegetarians, themselves, kill animals (usually).
That, of course, isn't the point. The linkage to the
actual animal killers is clear. It's even a little
amusing that Matheny has gone through all his gyrations
to try to show that meat eaters do in fact bear
responsibility for the animals they cause to be killed,
because I don't think most meat eaters ever think they
*aren't* responsible.

However, Matheny's analysis, as I said, clearly works
to establish "vegans" as being responsible for animal
collateral deaths, too, by exactly the same mechanism.
Some low-talent sophists like Dreck Nash attempt to
make the difference based on the "necessity" of animals
being killed in order to produce the food (necessary
for meat, supposedly not necessary for vegetables), but
Matheny's paper doesn't address that issue at all, as
it shouldn't.

When we look at one of the two criminal situations that
serve as analogies for the idea of complicity of
"vegans" in animal deaths - the accomplice in an
unexpectedly fatal bank robbery - we see that the
accomplice's complicity is NOT dependent on some
"necessity" of the unexpected outcome. That is, the
accomplice - say, the getaway driver - is already
responsible for the bank robbery, but if some innocent
person is killed in the course of the robbery, the
accomplice ALSO shares in the responsibility for the
death. If caught, his punishment will be, and SHOULD
be, harsher than if no death had occurred.

The "vegan" isn't the hands-on killer of animals in the
case of collateral animal deaths in agriculture, but
the dead animals are a foreseeable consequence of the
process, just as the dead bank customer is a
foreseeable consequence of an armed bank robbery, and
the "vegan" knows about the virtual certainty of CDs;
at least, Dreck Nash always claims she does.

"vegans" are morally complicit in the collateral deaths
that occur in the course of the production of "vegans'"
food.