hi Jakes,
Welcome. I'm also originally from South Africa and I believe there are some others on the forum. It's difficult to believe that any elder could get away with saying to someone they are disfellowshipped and "dont you dare appeal". I don't mean that I disbelieve you as I have come across my fair share of autocratic elders, but when someone is disfellowshipped they should be advised they can appeal. In fact, that brother has grounds for his disfellowshipping to be reversed (if he so wishes) as the action as you describe it would make the judgement unsafe.
How sad that one person can have so much authority that even the presiding overseer wishes to step down. Does this, perhaps, have racial overtones with a white person in a predominantly coloured congregation? I am sure in some of the smaller towns there could still be a residue from the apartheid years.
Earnest