That's certainly reassuring. Just so I can understand it a bit better, what do you mean by OS call error? What I'm gathering here is that if SysUpdater screws up installing a .cia it skips over it whereas KTM will try again to lessen the chance of this happening? Also what tipped you off as to the fact that it was a OS call error? TuxSH seemed not to know the cause of the issue in the thread, he only referred to it as a rare code corruption, but it seems to be the cause of a few permanent bricking cases so it's not rare enough imo.
It could be a code corruption indeed, but then I wouldn't be able to do much about it unfortunately.
Well, if the system just hangs like this, it's maybe because the system didn't answer what was expected by sysUpdater. Once again, first look guess.