That's weird to the point that I suspect your friend caught the flak from some kind of ongoing argument: maybe Excited Man is allergic, or his drains keep clogging, and he has been trying without success to get his neighbors not to leave dog hair around.
Yes, large clumps of dog hair can look weird on a nice green lawn, but that hair is nest-lining material for birds in spring and squirrels in the fall. Hm. Maybe he has been trying to get rid of squirrels?
(I'm guessing the ongoing-argument-with-neighbors because otherwise most people might shout, so as not to get close, but they'd be more likely to start with something like "Hey! Don't brush your dog here, my kid has asthma" rather than starting with the threat to call the police.)