Social responsibilities of dog owners

I was on a walk this morning with my baby and noticed a man walking with his dog, who I see often. This man is quite disabled, and when his dog pooped on the sidewalk the man couldn’t pick it up, he just continued to walk. It’s illegal here to leave dog poop on the sidewalk, but because of his disabilities the man couldn’t bend over to do it.

This dog is like a service animal for him, he helps the man cross the street (he finds where the sidewalk ramp is because the man can’t really look down, and could trip and fall), he directs him around obstacles, and he is obviously a close supportive companion.

What do you think should be done in this situation? Is it ok in his circumstance that he can’t pick it up?

Side note: lots of people don’t pick their dog’s poop up, and the sidewalk sometimes gets a lot of dog poop, you have to really watch every step as you walk/ bike. It’s also a pain in the ass with a stroller to try not to run any over at times. It isn’t just this one man leaving it, but he’s the only one I’ve seen who physically can’t clean it.