Of course the Germans will let him go in a few months, just like they did the guy convicted of 9-11 involvement, after his lawyers point out that the evil Guantanemo-running Americans were involved with collecting the evidence against him.
You got that wrong. Germany´s chief prosecutor is still working to get Mzoudi and Motassadeq into jail. The judges have heard that there was maybe material in the US which could prove innocence of both, therefore it dropped the charges until there´s further proof of guilt. Here, we have a concrete plea for extradiction, and there´s no reason for Germany not to extradite the guy to Spain (I hope that the Spanish have sufficient evidence for a conviction). And regarding Mzoudi and Motassadeq: both will get their penalties - if not in Germany, then in a country they will be extradited to.