I found this explanation of the German law in question:
Germany's criminal code says prosecutors and courts can agree to close proceedings in exchange for a payment, community service, reparations or other conditions "if the degree of guilt does not present an obstacle."
The possibility is available for any offense carrying a minimum sentence of less than a year in prison -- such as the charges Ecclestone faced, bribery and incitement to breach of trust.
It's generally used in cases where both sides are struggling to prove their case. The court delivers no formal verdict, but the defendant isn't convicted and effectively wins a legal stamp of innocence.
http://autoweek.com/article/formula-one/how-ecclestones-german-trial-closure-was-possible