Ontology Design Patterns show promise in enabling simpler, faster, more correct Ontology Engineering by laymen and experts alike. Evaluation of such patterns has typically been performed in experiments set up with artificial scenarios and measured by quantitative metrics and surveys. This paper presents an observational case study of content pattern usage in configuration of an event processing system. Results indicate that while structural characteristics of patterns are of some importance, greater emphasis needs to be put on pattern metadata and the development of pattern catalogue features.