gosh, I hope the dog attack didn't last as long as this thread is
So what the heck I'll throw in my 2 cents..First I think if Joe has had 4 incidents at the dog park, shame on the people who didn't report it, he shouldn't be AT the dog park. But not my call to make.
I am trying to put myself in relayer's position,,I "might" have approached this guy the same way he did, introduce myself, apologize for the situation, if the guy said to "me" what he said to relayer, at that point, (and I am definately not known for having a cool calm head at times especially when it comes to my dogs

I most likely would have said "ANNNND that's it, just wanted to introduce myself and say sorry"..then moved on..IF however, he told me to "screw off",,I don't think I'd have appreciated that much. At that point, I kill em with kindness, and say "And you have a wonderful day to"..and left

)
He said, she said, who cares? it's over and done with, go into your "zen" mode and enjoy your dogs