When calling in an area where there are bears it is important to select a site with 360 viewing, no blindspots. If you dont want a bear to come in then move from your spot after 30 minutes or so and go to your next location.
I have not called in a bear, but have watched recordings of it and talked with a couple hunters who have and have been successful doing it. Calling bears requires different techniques and requires long duration continuous calling. When the calling stops the bear stops coming in. So, if you dont want to see a bear, call in intervals instead of continuously.
If by chance the stars aligned and you were confronted by a hungry bear I have been in recent discussions with a state bear biologist who assures me that bear deterent does work and is effective. I worry about bowhunting without a backup, so have been asking questions about the bear sprays.
If you do shoot a bear in fear for your life I wouldnt suggest trying to "do the right thing" and take it home. Without physical evidence of an attack you will be cited if caught.