If people are nervous about the interaction, for instance, you mentioned Scooby's owner being nervous/excited about his dog interacting wither other dogs, that could make the situation worse. Dogs have a tremendous ability to sense the feelings of the people around them. If the people are nervous or anxious this could make the dog more nervous and anxious in response without an understanding of what the nervousness or anxiousness is all about. It seems like you have a much better attitude regarding the dogs interactions than Scooby's owner. Keep up the good work.