Daniel,
That was one of their least intelligent moves with flights in AR5 (or their sometimes brilliant ones in AR11). The "standard routing" from Cairo to Nairobi is via Addis Ababa and the best flight combinations take a total of 7 hours 50 minutes including layover. I recall that Charla and Mirna went via Dubai to get a flight combination that was better if they were not delayed into Dubai. However, they were delayed and that caused their elimination at the end of AR5, episode 7. Total flight times on that route not counting layover are 9.5 hours minimum, so that underscores the risk involved.