I almost lost a client because my AI system cited a lower court ruling as if it came from the Supreme Court

I build AI systems for professional services firms. During testing of a legal research assistant I built for a German law firm, one of the senior lawyers flagged something that could have been a serious problem. The system was asked about a specific GDPR interpretation. It returned a correct answer but attributed a lower court's expansive interpretation to the higher court. Essentially it said "the EuGH (European Court of Justice) ruled that X" when actually X was the position of a regional labor court. The EuGH's actual position was conservative.