When watching this video you can hear how the fisherman tries to help but little good it did.  The bear glances up at the fisherman after pinning the cow to the ground and looks rather aggravated at the fisherman for interrupting his meal.

It's said that bears have an excellent sense of smell, more so than dogs or any other mammal so even if the cow was able to run I doubt he could out run or out hide this bear.

This begs the question: what would you have done? Would you help the cow take down the bear or let nature play out? I know quite a few people who have some very differing opinions on how they would react. Everything from “It depends on if I had my hunting tools” to “I wouldn't postpone my fishing trip for no one”