This just in from OTBKB commenter, Petunia:

Your OTBKB reader’s nemesis is "clearly" in the wrong and sounds like a
miserable person to encounter w/ dogs or without, but that said, if
your dog is in a public dog run and has been allowed to get overexcited
to the point of "tussling," don’t let yourself off the hook so fast
either.

I personally avoid the Fifth Avenue dog run for these very reasons
– there’s no getting away from an overexcited dog, and a dog coming
into a dog run in that state can quickly cross the line from "play" to
aggression.

Often in those cases the owner isn’t paying attention to
the warning signs and then takes a "dogs will be dogs" attitude, which
can be a bit infuriating. Just because there’s no blood doesn’t mean
it’s ok for the other dogs and owners to have to put up with it.

[The OTBKB reader] said the other dog was out-of-control excited as well, which would make
a problem pretty inevitable. Just think about the playground, same
basic considerations apply – if one kid pushes another kid in
"excitement", then that kid’s parent needs to take charge, not make
excuses, whether or not anyone was hurt.

It doesn’t mean you have a
monster dog or anything, it’s not really the dogs’ fault – I just wish
people would exercise their dogs a little before coming into the dog
run, to take the edge off so problems like this can be avoided. There’s
an excellent Dog Whisperer episode about dog park etiquette I wish all
dog owners would watch.

So take your pooch for a good long walk before
letting her loose in the run, keep a closer eye out for signs of play
getting too rough for one dog or the other, and hopefully you won’t
have to worry again about some crazy dog person getting all crazy on
you.