Being results-oriented I'd say your play was good, as the cops got there quickly and no harm done to your person.

I do think the least you could have done was shout in their direction. I think this would subdue the guy just a bit, knowing that someone sees this.

I would shout without getting TOO close and then call the cops. You are probably right, he was probably drunk and you just don't want to get involved in that crap.

Anyone over the age of 25 has too much to lose over something like this! If you are under 25, I'd say being a hero is much more feasible.

This, of course, is just a huge generalization. All-in-all I'd say good play by you.