Getting back to dogs - I had an incident with a dog (ugly Staffy type thing) last year. When the idiot owner - almost as ugly and as stupid as the dog, failed to call it off as it launched towards me, I shouted "call it off" - which he didn't. I asked him to control his mutt and I just got a torrent of abuse which I retorted to in a more articulate manner. I think bad dog owners get abusive as they are feel some sort of guilt and "transfer" this to the other party in much the same way that people in road rage incidents blame the other and swear at them when they are the guilty party.
Don't worry about it. As some previous posts say there are different types of fitness. I can easily run a HM in well under two hours but put me in a pool and I struggle to do two lengths without getting tired!