to a guy at the dog park yesterday. BF and I took our 4 dogs to the park for a short hike. It was busy of course and we just walked through the park to the woods and trails beyond. Our dogs know the routine so they ran on ahead through the fence and up the dam. So did 4 or 5 other dogs though. Most owners realized their dogs were taking off and called them back. We paused on the hill to stop our dogs forward progression and allow the owners to recall their dogs then set off again. At the top we entered the woods and found that we were up one dog. A medium sized white and brown spaniel type dog. We paused at the juncture of the trails to see if we heard anyone calling for a dog, but the waterfall was pretty loud. I can't say that I remember if this dog ran up with us or was already up there, all I know is that he was running along with our dogs.
So we continue up the trail a few yards and this boy keeps up with us, I checked his collar to see if he had a name, but apparently Sidney was not his name. We paused again at this point to let a worried owner catch up, but no one showed up and we heard no one calling. In the past, dogs that have followed us, have left us and gone back to find their owners at this point. This boy stayed with us though even when we tried to ignore him at first.
Part of me felt like we should turn back and find his owner but the other part of me was like, well we have to go back that way anyway. So we continued on our walk. This is a predetermined hike for us and it doesn't take that long and at about the point where we turn around to head home, we hear someone calling through the woods. So we stopped our forward progress again and waited. We couldn't make out what the person was saying (even when we could see the guy, still couldn't understand the name). So he catches up to us and calls his dog, who runs to him. He then proceeds to grab the dog by scruff and muzzle, push to the ground and scold the dog for running off.
I couldn't let that go. I just couldn't. I walked back up the hill towards him and said something like, "Don't get mad at him. He came to you when you called." (which he did as soon as he saw his owner)
The guy was like he ran off and shouldn't run off.
I responded and told him he should always praise his dog for returning to him. No matter how angry we are, we should always praise them for coming back.
He tried to ask how do you correct a dog for running off.
I told him it was his responsibility to make sure it doesn't happen in the first place. That his dog doesn't know that he's angry for running off 20 minutes ago! That he only knows that right now, he came back to you and you're angry. If you're always angry when he returns, then he's going to be less likely to return in the future.
He said a Vet told him to correct him for it! 
I said no, you need to teach him a good recall but you can't get angry with him for running off.
I think the guy was a little put out that I was "scolding" him! I did tell him that I teach agility to people and their dogs so I know what I'm talking about. He kept saying "thank you, but.." He did say he loves the dog very much and would never hurt him. I said that's great but you shouldn't get angry with him. He's a great little dog, having fun and stuck with us very nicely without running off and when we heard you calling we stopped to wait for you. Oh well, maybe he'll think about what I said. Maybe he won't.
The dog was a very cute dog, happy, loved chasing our guys around in the woods. I hope he does think about what I said.