Andy,
I wouldn't say you shouldn't trust the updates, but as an experienced administrator, you should know never allow your servers to install patches automatically. You should be scheduling routine maintenance cycles for your systems. I would say this about ANY server environment-- Windows, Linux, Mac, or otherwise. This is especially true if you're doing work as a consultant... what would be worse for your customers-- paying you for an hour of routine maintenance, or paying you for several hours of troubleshooting a botched patch update?
In any case, what would you prefer Microsoft do here? Not even admit the problem exists, leave the updated posted, and then silently replace it with the correct version?