Looks like we're both kind of right. Your original source is solely based on LG Siegen 09.07.2013 - 2 O 36/13, which said service providers from non-member coun

Looks like we're both kind of right. Your original source is solely based on LG Siegen 09.07.2013 - 2 O 36/13, which said service providers from non-member countries don't require an imprint and the court's decision doesn't really align with what you said. However, the ruling was overthrown by OLG Hamm 17.12.2013 - I-4 U 100/13, which actually follows your interpretation of the law.