The only surprising thing about this is that it went this far:
Argentine Prosecutor Drops Case Against President Cristina Kirchner
Javier De Luca argued that accusations were spurious (emphasis added),
In a 27-page decision, prosecutor Javier De Luca argued that Mr. Nisman’s case against Mrs. Kirchner and others was spurious. “The constitution prohibits the initiation and continuation of a criminal investigation simply to determine if a crime has been committed when it is readily clear that no crime has been committed,” Mr. De Luca wrote.
. . .
The prosecutor is a member of a pro-Kirchner group, Legitimate Justice, which some members of the judiciary say is focused on protecting government officials. The group’s leaders say they are trying to reform a judiciary that had become too close to big corporations and vested interests. Argentina ranks 127 out of 144 countries in the World Economic Forum ratings on judicial independence.
De Luca also argued that the negotiations with Iran with members of Cristina’s inner circle cannot be considered a crime since conspiracy is not included in the Argentine Penal Code.
Although the judges from that tribunal can question the grounds of De Luca’s decision they cannot take up the complaint itself, sources from the court told the Herald yesterday.
. . .
De Luca’s dismissal came the same day that Nisman’s mother, Sara Garfunkel, along with a group of opposition politicians and intellectuals filed a writ before the Supreme Court to keep her son’s complaint afloat, something that is not likely to happen at the influential Comodoro Py courthouse.
As Capt. Louis Renault famously said,
Carlos Hos has a list of unanswered questions regarding Nisman’s murder (in Spanish)