The man would later die due to blood-loss, simply because those sharp incisors tore apart a vital artery. Although the man's friends tried to stop the bleeding , the 60 year old native succumb to his injuries and died.
Beavers , believe it or not, are as fast on land as they are in water. And those teeth that tear up trees can easily penetrate human flesh and bones. Not to mention, mother beavers, like all nursing mothers, are very defensive of their babies.
Look at this harmful serial killer