Unfortunate that had to happen and I wish him the best to be better soon
When I am walking in the jungle bears are a definite concern for me. last time I was in Kaeng Krachan there was a bear sited near Ban Krang camp near the road, Rangers tried to keep everyone away for a few hours as it was a mother and cub.
While in the USA I purchased bear spray, it shoots up to 20 meters and attaches to my belt loop. I get some degree of comfort knowing its there for bears and possibly even a charging elephant