we just encountered several DL emps doing similar via windhoek
they were the ones who didn't get up front yesterday (we left day before) and they were 1989 DOH using high priority
Sorry I didn't get their email to find out more.
The other emps we came in with had to skip a day in CPT and get to JNB due to minor holiday that choked the flights for the wkend
What are your zed options besides LH via FRA?