Bottom line, IMO if you have made the initial call to 911, fully informed them of the situation and how you handled it, and the police don't seem interested in pursuing, then apparently the guy either didn't or isn't going to file a complaint and the police are not concerned unless you do. Or, they felt it was justified and until there is something to investigate like him filing a complaint, then no biggie. I personally would not call and bug them about it or they may decide there is more to the story than you have told them and try to dig up dirt on the event, but more than likely since there was no use of deadly force, and apparently no report filed by you or the other person, then they probably look at is a no harm, no foul event and something they don't have to spend time on.
I haven't posted this, but last Friday I had an incident that I was involved in and had to call the police. I will post that at some time for a situational awareness topic, but don't have time at this moment.
In the end, I would say let sleeping dogs lie and if you have fed the police all the basic information, then the ball is in their court to follow-up. Remember, the first call to 911 is usually the good guy if done quickly, and the police will usually interpret it as that.
