I imagine it was just a case of "enjoying" the win a little too much. I imagine a few gloating words were said, but on the merit of the penalties alone - not to mention the complacency of the Argentines in taking of Riquelme, Germany totally deserved that win.
What I love is that even though the match had techincally finished - Argentina's unused substitute Leandro Cufre was shown a red card for kicking Germany's Per Mertesacker in the melee.