I don’t believe this is a straw man argument, I never claim that they believe these conclusions. Quite the opposite, I am showing how their argument, not their conclusion, is not good. As I understand their argument, it is basically this:
(i) If something does not want to be killed, it is morally wrong to kill it. (ii) Animals do not want to be killed. Thus, it is morally wrong to kill animals.
I do not agree with (i), which I try to explain by reductio ad absurdum, arguing that if (i) is true it leads to obviously incorrect conclusions, thus (i) must be false.