If you have a doubling of reported air traffic controller mistakes, does that mean that safety has decreased?

Or is it because of a new program that gives controller immunity for reporting certain types of mistakes?

Or is it because the FAA started a crackdown on “under-reporting” and coverups of mistakes?

Or is it a statistical annomily?

Or some combination of the above?

See the CNN story and you still won’t know:

http://www.chron.com/disp/story.mpl/business/7422939.html