Apparently there were two dogs fighting in my neighborhood

I heard a lot of not-too-distant barking while I was inside that went for a bit. This was constant barking from two dogs, but I figured must've been one of the neighbor dogs barking at something. A few minutes later, I took my baby outside just give him some fresh hair and there was this old man passing by walking his dog. When he got closer, he asked if I had a phone he could use to call the housing security because another dog just attacked his dog! I let him use my phone to call security and overheard the whole thing. He explained he was just walking his dog when another dog jumped out from the yard of a nearby house and just went after his dog and the man had to break them up. Yikes! He seemed like a nice old man too, he was all saying "I don't want anything to happen to the dog, I just want his owners to keep him put away better." And this old man's dog is a German Shepherd. If that dog will go after a German Shepherd, it'll probably go after any dog! Our housing complex has some pretty strict rules when it comes to dogs, so I imagine the owners of that dog will be getting a good dressing down for that. I'd hate for anything to happen to their dog too over their negligence.