My point was that this METHOD of argument is faulty. I just threw together some quick examples of the style, I wasn't making an actual argument with any of them.
I'll use the example you provided though..."It's basically the same as those in support of the death penalty having some responsibility when one innocent man is executed." The problems is that your statement is not exactly wrong, it's the conclusion that's often implied with statements like this that is wrong.
Yes, if you support the death penalty, you DO bear some responsibility when an innocent person is executed. But the only reason anyone says things like this is that they silently add "...therefore you're wrong to support the death penalty." It's a bad argument, since no position is completely without negative side effects. And while those side effects should certainly play a part in forming an opinion, they shouldn't be the ONLY thing that's considered. Not to mention that these specific situations are almost always framed as emotional appeals, which tends to cloud the issue even more.