I don't have any experience at a dog park. We don't have one.:( But it's natural that every dog isn't going to get along. Every being cannot possibly get along 100% of the time and dogs just have a different way of showing it. You sound responsible and I can't understand why an owner with a dog that is much bigger than yours would get so uptight. :confused: If it were me, I'd be more concerned for the little guy. But then again, I wasn't there.