I don't actually agree with your assessment. But let's leave that aside as we'll likely never agree.

Right now though - the more important message is the one that's in the article: this is a reason to trust the DA more. Alone among all South African political parties, this one has shown itself willing and able to severely chastise a senior leader (with strong struggle credentials no less) for screwing up. How much better off would we not be if ANC leaders who did fundamentally stupid things got this level of punishment every single time ?

This is something we should all be in favor off. Even if you feel her offense was not so bad - you should be glad that the DA is setting an example of actually punishing people who broke the rules (even if you don't agree with the specific rules).  Even if their past behavior was heroic. 
We need to spread that attitude throughout our politics, not complain about the one party that actually has it.