While the motivation for my action was my love for Sam, my choice may have given me greater odds of survival than running away would have in this instance. I would have been running towards the end of the portage where my gear was but my canoe was still at the beginning of the portage. I had no way to truly escape the area and would have been left with the difficult possibility of facing this bear, when he was done with the appetizer, in a frontal attack armed only with the knife. What would I have done, offered him my one arm to chew on while I stabbed with the other? Of course none of this was going through my mind at the time, I only saw my beloved canine friend being attacked and an opportunity to stop it.
Some years back there was a book written called The Gift of Fear The author interviewed people who had gotten away from serial killers - the few who had lived through the process. What he discovered was very similar to what happened to you. The survivors acted on instinct - and made choices that they were later able to explain, but didn't understand while the event was happening.