Actually, they don't own that area where your dog pooped. That's the city's/town's property. If your dog pooped in their yard, then that would be a problem. But your dog pooped in the grass between the sidewalk and the road, correct? Then that's fine. I wouldn't worry about it. If that were a crime, I think 90% of PT people would be in jail - myself included.

Just my .02 cents.