The reason you're seeing JSharp unblocking Charitwo is because a global block does something strange internally. The software knows the user is blocked, so displays the blocked tag on his profile and the last block long entry for that user it can find (if it exists). The actual log entry for the block is handled by something different and private, hence you see something confusing or nothing at all.
I am a little consufed about this question, as I ask myself what was your question about, about what cqm explain or why the block should be discussed between the blocked user and Staff. I will be answering to the second one. If you think about it would only make sense for the block to be solved between the person who was blocked and Staff and not between an outsider and an admin who after all did not block him. (this case being you and Ozuzanna).
The block is done differently due to the standard block only affecting a single wiki. If you wanted to block someone on every wiki, you'd spend a fair bit of time going through hundreds of thousands of wikis blocking someone. And if you decided to alter that block or remove it, again you'd spend a fair bit of time doing so. I believe some other wiki farms use a user group to mimic a global block, which simply unsets all the user rights associated with normal editing. I don't know if this was explored/considered instead of the current system or if it was rejected for any reason. I do know the system is meant to be very good at what it does and was ported to a standard extension (a lot of wikia's extensions don't work on standard mediawiki installs) for use on other wiki farms and a very similar project was being considered as part of Google Summer of Code.
As for why they're private, some global blocks can be for legal reasons. One example is for COPPA violations, if everyone knew the user was underage then it could lead to someone actively looking for their information. If they find that information, it could leave Wikia in an uncomfortable position in a legal sense (I don't know the workings of the US legal system to know what the consequences could be). It's safer for people to not know in this case. Whilst there might be another case where it's acceptable for other people to know, it's easier to just hide all of them which leaves us with the system as it is now.