[Z-man]

Maybe it was rabid? If your neighbor ran back - then I could understand why the coyote would attack - but you said he backed up. Also - if the little dog pee-d on the man, that could cause a coyote to get a little wild. Or maybe the coyote's offspring were on the other side of the yard, and your neighbor got between them.

Wild animals are unpredictable - as much as we think we are on the top of the food chain -- sometimes the tables can turn on us.

-Z