The rules for safely watching bears in nature are there for a good reason.  Never hike alone.  Always make noise while hiking.  Carry bear pepper spray.  Etc.

I like to make good pictures (and of course, live to tell the tale).  Hence, I'm in out in nature a lot and regularly in areas with bears.  Mistake #1, I try to be quiet while hiking so to not spook the wildlife and miss my photo opportunity.  Mistake #2, I like to hike alone.

While on a hike - by myself - in Yellowstone National Park, I spotted a big black bear grazing across a river.  I was "safe" so sat down in the brush to photograph the unsuspecting bear.

Long story short: for whatever reason, the bear decided he wanted to taste the grass on the other side of the river - my side - and swam across almost directly to the spot where I was sitting.  I immediately stood up, said "hey bear", he saw me and came ashore a little next to me.  Not interested in me, he continued what he was doing.

I carry bear pepper spray for the "what ifs" while hiking in bear territory and have never been threatened.  That being said, the rules for safe bear viewing are t here for a reason.  Both for your safety as well as the bears.  We have to avoid habituating bears to humans as that inevitably leads to trouble.