It's unusual for a Coyote to attack an adult human being

 Mostly they go after dogs and cats or small children. But, unless a Coyote is interbred with a Wolf or something (which is possible by the way) they don't usually go after adults, even women. A wolf by the way doesn't bark at all even though they might howl at the full moon. They also can run backwards (I have seen this myself) they do this to protect their hindquarters from attack. A wolf is almost as smart as most human beings so it isn't a good idea to get on the wrong side of a wolf, especially if this is a wild wolf and not a  domesticated one.

Did the Coyote have rabies? This might be the only reason a coyote might attack an adult human being.