Steelers DB lights up Willis McGahee after he makes a reception over the middle.  McGahee fumbles and it's ruled as such (right call).  Looking at the replay, it was CLEARLY a helmet-to-helmet hit and there was no flag.  Why no flag on this, but NFL referees will throw flags for much more minor things? (D-lineman's hand accidentally brushing a QB's head while trying to deflect a pass)  I thought football referees have time to "Watch the play develop"?  If they have so much damn time, why can't they get stuff like this right?
Edit:  
http://www.youtube.com/watch?v=QfS9KQsExgs
(This one really takes the cake!)
http://www.youtube.com/watch?v=d9KmXAmMTjw