I don't think it's anything exclusive to cat sailing. It's sailing in general - the majority of regatta results produced these days contain mistakes.

But these results are worse than usual. You don't have to accept them as they are. If the club isn't prepared to fix up their results and publish new ones you should talk to Yachting SA. They should be right on to this as it's really bad for the sport. Hell I'm inclined to contact them myself. But best to ask the club first.