Bears are ranked first because they've had a lot of defensive touchdowns which is worth more than anything. Top NFL defense has nothing to do with the top fantasy D. The team with the most turnovers/sacks/TDs will be first.
"Kobe first injured this shoulder in the preseason, according to sources. Has been playing w/ it all year. It just got worse last night"
After suffering the injury, he simply started shooting with his left hand rather than leaving the game.