Definitely need to recheck bags in JNB. We had a 1h45 connection to DUR and almost missed it because it took over an hour for our bag to hit the carousel. Our bag never made it to DUR and came in on a later flight. I've usually skipped connections due to large queues and checked my bag at domestic although connections desk may be more lenient with the 45 minutes prior to departure rule (they were for us).