|Skilled person reproducing the prior art|
This is, however, hardly perceivable in real life patent nullity appeal proceedings because the discussions mostly turn around the question of patentability, sometimes enablement and all of these are considered to be questions of law (see e.g. BGH "Stabilisierung der Wasserqualität") and therefore fully re-examined in the 2nd instance. The above exclusion of questions of fact is therefore, in practice, mostly limited to factual circumstances of prior use.
In the decision "Coenzym Q10", the BGH establishes a further group of cases where the examination is precluded. It relates to the specific case of implicit disclosure where carrying out the teaching of the prior art is said to inevitably lead to a product falling under the scope of the claim, wherein the product itself (or the properties thereof) are not explicitly described. These cases leave plenty of room for speculations on what the skilled person might or might not have experienced when reproducing the prior art.
The BGH rules (in a rough translation by the author of this note) that ".... judgements of the Patent Court supporting the conclusion that reproducing an embodiment in a document of the prior art lead to the realization of a feature of the subject-matter of the patent in suit are binding for the appeal procedure unless specific indications justifying doubts in their correctness exist".