Even with fairly boring usage, the Github GUI periodically wedges my repository into a state which requires CLI interaction (and a trip to stackoverflow). It's even worse for newbies - I get desperate pleas for help from clients all the time. I have come to the conclusion that there is no way around teaching the command line first, then giving them the Github client after they achieve competence.

No, I have not tried to reproduce the incidents which screwed up my repository. After a few harrowing experiences I pretty much gave up using the Github for Mac client for anything except basic commits. And even that screws up - I frequently have to commit files twice; it's like the client only stages some of the files, even though they're all checked. If my commits are large I usually go to the command line to avoid the double commit msgs. I'm about to give up entirely.