I went to a seminar in Cody, WY on how to live with bears, loins and wolves. I also have a life long friend who teaches bear avoidance for Northwestern Energy, the dominant power company in Montana.
First of all you don't have to out run your partner, you just have to knock them down or trip them. I'm sure that that 66 year old has many tricks up his sleeve.
With weapons there is a 50 % success with Griz bear attacks. With bear strength pepper spray it is 90 %. I like the odds with spray 10 % chance of being eaten vs. 50 % chance of being eaten.
I did see severral videos and that spray really works. Aim for the face. It works on mucous membranes and is 10 ctimes stronger than mace. It uoght to take care of all those demented cfrazed hikers too. No need to pack heat.
Keep the spray handy. It is no good inside the pack or in the vest.
The lead instructor said that he has had to use his spray twice in his 20 plus years of backcounrty travel. (From the map of 2007 bear instances, that would be any where 2 miles west of cody and beyond. There is some really good Cutthrout fishing there. It figures.
Also if you have bear spray then get that neat plactic jar to contain it. The instructor had a really neat story about a gamewarden that had oine go off in his vehicle. The can was set off by the high heat generated from the summer and rolled up windows.
The stuff also works on the other critters. If you are worrid that pack the bear spray in atleast 9 oz volumes and makes sure you know which way the wind is blowing.