"Because medicine isn't a science"
- Dr. Spaceman, 30 Rock.
But seriously, because these things aren't black and white. I know certain posters like to portray the Canucks as chronic mis-diagnosers, but the fact is, it often takes multiple examinations to determine exactly what an injury is, not to mention how severe it is, and then it's still not always clear what the best course of action for repairing it is. Sometimes waiting to see how the body responds really is the smartest choice.