Actually, JNB-ATL is (usually) 2 hours longer than ATL-JNB, as it's into the wind. (see the OMG DAL 201 thread below)

The key word in the FAR Duty Limit has always been "Scheduled". As long as you were not originally Scheduled to exceed the FAR's, you are good to continue. If in the event of a delay after sign in, either weather or MX, and now you go over the FAR max, you were still ok to continue. The company obviously has to build the rotations in compliance with the FAR's, but when the crap hits the fan, you can go over the FAR's.

So...in the new regs, did they remove the word (or concept) of "Scheduled" duty time, vs. Actual duty time? I remember when the Whithlow letter came out, that was the intent, to look back and see how many hours you'd been on duty and not allow you to take off, if by the time you landed, you would exceed the max duty day.

And, yes, they do have a lot of trouble covering the late DXB and JNB trips with short call reserves, if they are MX delayed, because the guys on short call are considered on duty (or not on rest) and then have a long duty day ahead of them. That's why at 2am, they get covered by green slips more often than by short calls. The short call guys have been on call too long to show up at 1am, and be on duty for another 16+ hours.