If the guy pointed the gun at the cop he was in the wrong. He started the situation. But I'm giving him the benifit of the doubt, thinking he is smart enough to know that pointing any gun at any cop is a stupid idea.
The cop was off duty so (and not making excuses for the guy) did he accidently "sweep" the cop while he was in civilian clothes or was he in uniform? These are all things you have to take in account. I know most people try not to sweep anyone but sometimes it happens. And how do we know how he "pointed" the gun at the officer? Did he aim it at him or did he just sweep him? Or did he even do it at all? There are too many open ends on this story.