No sanctions for 'Golden Boy' Rosberg

Cleared by the stewards of pushing Alonso and Hamilton off the track during the Bahrain Grand Prix it seems Rosberg really is the 'man of the moment'.  There was a large run off area, but surely the rules should be the same whatever the driver is being pushed into.  In Hungary 2010 Schumacher pushed Barrichello into a wall and received a 10 place grid penalty for the next race.  How is this different?  Does this ruling give drivers license to use the run off areas as part of the track from now on?
 
Why weren't these incidents investigated during the race?  In Monaco 2011, Lewis Hamilton was given a drive through penalty during the race for an overtaking move on Massa.  There seems to be one rule for golden boy and one for everyone else.

Lewis and Massa in Monaco 2011. 

Investigations by the stewards do seem detrimental to the excitement of the racing and can prevent drivers from really commiting themself to a move, but if they have to happen, the judgements must be consistent.