well.. I walk three dogs... it is a funny site I can tell you
I have had the same experiences a few times, some people should not have dogs. I will say I had a little Pom that was a runner. Several times, after chasing him for HOURS, I would get a call from someone who found him. *sign* it did cause a lot of stress. I alternated between wanting to kill him and crying out of fear he was hurt.
Now.. to your troubles... I like the "hiding him" for a day - and then "finding" him down the road and being the "hero". At that time you could offer the advice.
I wish you luck