The problem I'm pointing out is the difficulty of finding ways to deal with people that refuse to live by the NAP when you are restricting your own actions by it. If someone messes up and takes responsibility for their actions, there's no problem. However, dealing with, say, a serial killer or serial rapist is something fundamentally different. That's not the sort of person that you can just leave alone to live freely in your midst.
Calling in a "dispute resolution team" to solve the issue is not an answer. What would they actually do? If they're expected to make decisions and do things that other people aren't free to do, they're no different than police.
The way I see it, there are three general ways that communities can deal with violations of the NAP. The first is forgiveness, the preferred method that would be used most often. In the case that a person understands that they did something wrong and works to make amends, they should be welcomed back into the community. The omission of forgiveness is the fundamental problem with our current system of crime punishment. It's a permanent mark that creates an oftentimes insurmountable hurdle into reintegration of offenders, which creates resentment and and inability to participate in healthy interactions which drives a person back into destructive behaviors. With forgiveness, we open a path to healing, reform, and, perhaps, honest compensation for the wrongs committed.
Second is sanctions of some sort. In the case that a person refuses to admit fault, but their violations are minor, sanctions can be used as a sort of material peer pressure to induce compensation. This can include embargoes, increased fees for goods/services rendered, or other passive aggressive non-aggressive methods. For whatever reason, this seems to be the preferred method of NAP proponents for any and all offenses. For society to function in a healthy manner, this should be an alternative option for repeated violations or more egregious violations in which the perpetrator does not take responsibility, not a go-to solution for everything. It creates resentment and desperation, which, as I said before, increases the likelihood of further violations. I cannot stress the importance of forgiveness enough in dealing with most problems.
Last is removal of the perpetrator from the community. This would be used in the case of a person who refuses to live by the NAP, violates it flagrantly, and whose continued presence or existence is a clear danger to other individuals. Make no mistake, "removal" means either exile or death. Imprisonment is just a form of slavery, so it's not an option. Obviously, any way you carry this out, it is a violation of the NAP. However, it is completely necessary for the sustainability of any society. This should be a measure of last resort, but to deny it completely and simply wait for an opportunity for self defense, hoping that it will be successful, is insane. In a best case scenario, the outcome is the same as just executing someone, while in a worst case scenario, there are more victims and a greater potential exists for the dissolution of the community because, obviously, it doesn't protect people from violent murderers, rapists, et al.
So, while I don't recommend violating the NAP to enforce the NAP on a regular basis, in some situations it is necessary for personal survival and survival of the community. Waiting to witness a violation of the NAP by a person who is known to violate the NAP, merely so you can frame punishment as self defense is, like I said, self-defeating and wasteful. Some concession to necessity must be made within our understanding of the NAP so that it can actually flourish as a way of life, otherwise, we are putting ourselves at a severe disadvantage when dealing with those who mean us harm. There are some very difficult distinctions to make, but we need to figure them out, or this idea will simply fail and people will, again, clamor for the false platitudes of rulership.