That's a real cutie, Bob, congrats. Protip: In future take pic of said dog and said owner - actually several of them - and several of them together to show it's, in fact, his dog, then call City Bylaw and report him. At the very least he'll be on record as a problem owner so if, and when most likely, he does get popped for being the jackass he is they'll know it wasn't just a one time thing and treat him accordingly. If you're running into him at a certain time, even better, because then they can show up in that time frame to pop him. What's the pooch's name?
"You have enemies? Good. That means you’ve stood up for something, sometime in your life."