There are often two types of thinking involved in a situation like this. There is the emotional response, and there is the legal response.
The emotional response is just that. It is colored completely by emotion and is based on what is felt to be "right", what is "wrong", and generally concludes with "how things ought to be".
The legal response is pretty much emotionally sterile. It is based on a set of established facts, or elements, and how they apply to the raw unvarnished facts of the incident. It has written, established standards of what is "right" and is "wrong" and cares little for "how things ought to be" beyond what is written, and how these written facts have been interpreted by reasonable people in the past.
It is the emotional response that often gets people involved in these situations, and often colors people's judgement after the incident has been disposed of legally.
It is the legal response that matters, and often causes defendants to wish that they had considered the legal ramifications of their actions more, and the emotional ones less.
In short, you will be judged based on how the elements of your actions are interpreted under the law. Very little consideration will be given to how you, your friends, your family, or the public feel about what you did. The sole exception being whether you can make a convincing case that you legitimately felt that your life, or the life of someone else was in immediate jeopardy. That will probably be the only time your feelings will matter, so you better not blow that part. If he had to chase this guy down to choke him out, he badly blew that part. No other feelings that he, you, I, or the cosmos has had, have, or will have are going to matter. All of his actions will be examined under the sterile lamp of the law, and a decision rendered based on that sterile examination.
Of course things do not always work that way in real life. The OJ case comes to mind. But it is the way that things are supposed to work, and in most cases, probably will.