it seems like the guy is almost making a point - he's probably either a yewt or making a point to a good kid. That being said, I try to let me kids know not to be afraid of those kinds of things. I had some neighbors come over with beers in their hands. They apologized and offered to leave them outside the door. I invited them in. My wife said, "but don't be offended when one of our kids gives you an earful."
They decided to leave them outside.
Naw - you should be concerned. I just mean let your son know he isn't evil because he poured draft beer, but recognize what the man was probably trying to do.