It wasn't a really tough foul but a foul nonetheless. Pro's should know that reaching for the face of your opponent with your hand stretched out will always be punished. That's just the way it is. Stuff like that may work in a one-goal backyard kiddie match but not in a WC. The headbutt attempt also was childish and uncecessary. Pepe would have gotten away with a yellow, but noooo...
A referee with common sense would have given a yellow to both.
Pepe is obviously a moron, but Muller wasn't a saint either.
In the end, he got pretty much what he wanted.
With 2-0 on the table and a player less in the pitch, that was nothing more than a walk in the park.
Pretty un-necessary since Deutshland would win anyway.