Although I have a hunch I know the answer, it would be interesting to know the real figures on:
1) how many grizzlys attacks there have been over the last few years
2) in how many of them was bear spray used
3) in how many of them was a firearm used
4) which deterrent has a higher instance of ending with a more favorable outcome for the human
As I mentioned a bit earlier on in this thread, the
only study I've heard about found that bear spray was effective at stopping aggressive bear behaviour in 92 percent of cases while firearms were effective in 67 percent of cases.
This was a study of 20 years worth of bear encounters in Alaska; the bears involved were mostly (70%) grizzlies with the remainder being blacks (there were with a couple polar bear incidents included in the study too).