People are often killed riding on sidewalks, I avoid riding on them because they are very dangerous wherever there is a driveway - cars move to the edge of the street without expecting a vehicle moving at 15mph+ on the sidewalk.
Trust me, I know. I always slow down to walking speed when I'm approaching a drive-way or a parking lot exit.
The thing about riding your bike on the sidewalk is that you, as the cyclist, can avoid virtually all danger by being cautious. Whereas on the road, you're pretty much at the mercy of car drivers and are at great risk regardless of how careful you are.
Nothing in that paper talks about people being killed as far as I could see. Higher event rates != higher deaths. Running into another bike was considered an event, but that's not generally deadly.
