The latter one-year term is usually considered an absolute one esuring legal certainty for third parties and expires irrespective of the reasons for the failure observe a time limit.
The Starting with the decision "Überwachungsvorrichtung" in 2009, the 10th senate of the German Bundespatentgericht and the BGH have develpoed a theory allowing for a re-establishment of rights even after expiry of the one-year term. The most spectacular decision "Crimpwerkzeug III" ( ZR 193/03) reported here and available (in German) here, the BGH granted re-instatement into the delay for filing new grounds of an appeal against the decision of an upper distruct court not to admit revision to the BGH because the new grounds related to contradictory claim interpretations in judgements, wherein the (binding) interpretation of the BGH was available only after the expiry of the delay.
In a very interesting new decision availabe here, the 10th senate of the Bundespatentgericht granted re-establishment of the right to pay the filing fees almost 2 years after the expiry of the time limit. The applicant had filed an application containing only claims and the office had informed him that the minimum requirements for the filing date were not met because a description was lacking. The office furhter noted that any fees would be refunded and that a new filing date could be obtained by filing complete documents.
The applicant responded by arguing that the claims would sufficiently describe the invention to qualify as a description. The argument was found convincing by the examiner who decided to keep the application pending. However, the office did not inform the applicant on this decision. The applicant got aware of this decision only after almost two years, when the GPTO notified the applicant that his right was lost due to non-payment of the filing fee.
Following the "Crimpwerkzeug" theory, the senate judges that re-establishment may be requested even after expiry of the one-year-term
"in specific exceptional cases for reasons of ensuring an effectice legal protection and the right to be heard, in particular when the reasons for the failure to comply with the time-limit do not lie in the sphere of the party but are rather to be assigned to the court/office".