The situation you are describing is a proven association between certain stimuli and a known response. Kinda like pavlovs' dog.
Every time I go out to cut wood in the fall with the chain saw deer show up to get the leaves and foliage (where I live deer overpopulation is a big issue and they are very competitive for food). Anyway, if hunting in bear country I would assume the same as you have mentioned with gunshot then bear showing up shortly there after for dinner. I would definately carry a large bore backup pistol or leave the rifle in close proximity when field dressing the animal.
As far as a dog is concerned, in many states it is illegal to hunt with dogs for deer and other "bid game" animals so I would read the regs first and I would also want to have a very large dog (more aggresive breeds like rot, mastiff, wolf hound the better) who would at least keep the bear occupied while I could get off a shot at the bear, instead of running away and leaving just an angry bear and me to duke it out.
Lifetime member VFW and NRA
"Quando Omni Flunkus Moritati" (when all else fails play dead) -Red Green