Another Dutch giving his 2 (euro)cents:

>There was a clear penalty for Mexico, where a guy was actually kicked in the head, no diving there, no embellishment, but an actual kick on the face to a player trying to head the ball (see attached). I did not see the officials making it up for that missed call.

Actually, as easily a free kick could have given against the Mexico player for "Playing in a dangerous manner"

From the official FIFA Laws of the Game ( http://www.fifa.com/mm/document/footballdevelopment/refereeing/02/36/01/11/27_06_2014_new--lawsofthegameweben_neutral.pdf )

Playing in a dangerous manner is defined as any action that, while trying to play the ball, 
threatens injury to someone (including the player himself). 
It is committed with an opponent nearby and prevents the opponent from playing the ball for fear of injury. 

By trying to head for the ball that low, you risk injuring yourself. Because the Dutch player hit the ball first before the Mexican (which you obviously cannot see from a still picture), it is not an automatic foul, and it is up to the referee to decide if it was played in a reckless or dangerous way and by whom.