The W is really narrow with sharp points, that fine detail would be subject to die chipping. The lower loops of the 9s in the date are also most likely affected by die chipping as well. However, the upper part of the first 9 shows an area too linear to just be a random die chip so I am a bit stumped on that one
Nothing lines up for a clash and I doubt that the South African Mint was still performing any manual punching on dies by the 1990s so my best guess would be some sort of die damage(gouge, dent, etc).
























