For the sociopath's part, I don't think we're motivated by feelings of shame or embarrassment, although I hesitate to make a completely categorical statement.
This is not to say that sociopaths do not come up with stories to explain their behavior, sometimes seemingly outrageous stories like "I killed him because he looked at me funny." They can and they do. But everyone wants to explain their behavior. It helps give them a sense of purpose, of self-knowledge, and more importantly of control. If you don't know why you do things, then how do you know that it is even you who is choosing to do them?
The sociopath killer who says he killed someone because of a funny look is not attempting to justify his behavior so much as explain it to himself. And it is an explanation. Maybe the killing was an impulsive act, but it was prompted by something, in this case the look the victim gave him. Perhaps a sociopath might take it one or two steps further and add "I don't allow people to disrespect me," or some general opinion about the small value of human life, but the sociopath is just reflecting on the "why" of the action, not the "what does the fact that I have performed this action say about me and my own concept of self?" So unlike narcissists, sociopaths don't need to justify their behavior, but they'll still seek to explain it.
Another question the narcissist had was how sociopaths view the bad things we do to other people. He gave this example of how narcissists view this sort of situation:
E.g. take lions that eat wildebeests. The narcissist lion has to convince himself that the wildebeest has it coming to it, or that the lion is doing the wildebeest a favor by eating it. I'm wondering if the sociopath lion has to engage in that sort of self-deception, or if it can just eat the wildebeest and not give a shit.
I don't think sociopaths really blame people so much as attribute their failings back to them. Using the lion example, the lion doesn't think the wildebeest is a bad person "so it had it coming." For the sociopath, life is a survival of the fittest. It's enough for the lion that the wildebeest is unable to defend itself. Why did the wildebeest die? In the sociopath's mind the answer is not "because the lion killed it," but "because the wildebeest couldn't run away or defend itself adequately." That's what is really happening when it seems like a sociopath is blaming someone else for the sociopath's own actions. It's more an assigning of responsibility on the victim for not being more vigilant than it is a justification of self according to some rigid construct of being a "good person," like narcissists do
Sociopaths do not view the entire world through the lens of self as much as narcissists do (not surprisingly). Narcissists tend to think that everything that happens in their world is some sort of direct reflection of them (good person, bad person, whatever). Sociopaths understand that they are just a cog in a machine. While they don't completely give up on that idea of cause/effect and personal accountability, sociopaths are much more inclined to believe that what they do is perhaps meaningless. As arms dealer
Viktor Bout said, “If I didn’t do it, someone else would.”