Bring a rifle. Even the much-maligned .30-30 is twice as powerful as a .44 magnum.
Bring both.
Unless he would have spined or brained it, the bear most likley still would have had half a min or a min to do some damage even if he would have taken the heart and lungs out.
Doesn't take them long to do some very serious damage saw some pictures of a grizz attack years ago the warden and his helper thought the bear was on him for about 30 seconds it did a bit of damage in that short time.
I wonder what cailber of rifle and what bullet he was using . He most likely was hunting black bears at the time. Being armed is a very good thing I now carry a TI 41 mag back packing When one sees a big bear one always wishish for something bigger. But when one is out humping the mts for a week one wishish for something lighter