It probably wasn't a dog, I've got a big old black lab (named Max of course) who still loves to chase any deer he sees. Problem is that if it's only one dog most of the deer seem to only run so far before chasing back.

That deer was in mortal terror. A dog that puts that much fear into a deer is going to bark like all hell. You would've heard it. To scare a deer that much a wolf would not have been alone, you would've seen it.

I say it was a dominant deer asserting his authority. Deer will fight outside of the rutting season especially if food is involved and there isn't enough to go around.