Like Moggie, unlikely to shoot in either situation. Too unlikely to kill the bear and too uncertain about the man's intentions.
I do carry bear spray when they're awake, though, and at 15 feet, I'd be using the bear spray on a bear.
With a man, I'm always out front with my words, greeting him cheerfully (no matter how I feel that day), engaging as a person, letting him know I see him and am noting him.
I am 5'3", around 140 lbs.