You're applying "thought" to any cerebral function whatsoever? That's silly. "Thought" is generally used for conscious processes only. If a "thought" is unconscious then I don't hold anyone responsible for it and neither should you. At that level it's just an involuntary response -- an emotional response.
Reflexive, involuntary responses can be learned. In humans they're ALL learned. We have less than half a dozen truly instinctive responses. Just because they're learned, however, does not make them voluntary or readily accessible to conscious control. And if some response isn't accessible to conscious control then I don't see how you can possibly assign blame -- or any moral judgment at all -- to the response.
Returning to Earth, emotional responses are generally beyond one's control. They simply happen. How one reacts to these impulses, however, is not at all beyond control. If one's emotions become too violent or powerful to control or deal with then one needs psychotherapy. That's what therapy is for.
The original reaction was clearly conscious, the initial reaction was taught.
Also, emotional reactions are not beyond your control or therapy would never work, at all. The idea that they are not "readily accessible" is totally beyond all logic. You can find the reason, with introspection, and train new responses. This is taught. All that you are, including your "instinctual" reaction (not instinctual, that is hardwired and would be more like eye color or hair color, but those are not emotional, they themselves are stimuli), has been created by your thought.
If your weak argument here were all that could be applied, we could then assign no blame to those who emotionally react to those of different pigmentations, their excuses could be, and often are, the same. "I can't control my emotional response to... " insert whichever group you want here. It is the very description of prejudice. You have prejudged, you have taught yourself to respond in such a way, and you use that as an excuse because you "cannot control" such a response. It is hogwash for the bigot, it is hogwash here. You have allowed yourself to be strung along by those who would split the US into two camps who can never cross.
You have become a tool of separation. And your very excuses fly into the face of what you have been taught of prejudice for most of your life.
You accept this as an excuse because you want to feel okay about wishing their death, because they first "hurt" you by calling you "unAmerican" or whatever supposed justification you have for vengeance.
Desh had the right of it, you look less in everybody's eyes for using such a lame excuse to declare your actions to be okay, while at the same time rejecting the excuse for another group's actions (the unAmerican slander).
You are right, we can disagree, but you will never regain what you lose through your actions.