When posted abroad - and most certainly in Germany - almost all offences within the community are heard by Courts Martial (whereas in the UK, very serious allegations, such as rape and murder, are heard in civilian courts). This also applies to 'dependents' (a dreadful term) and UK civilians working for HM Forces in-country. Why? It is to ensure that UK personnel are subject to 'British' Justice. Imagine if an SP was accused of similar offences in, say, Saudi Arabia?*
* Probably acquitted, that's what!