OK. I don't know, this could just be nothing, or maybe something. I discovered it while changing some eboot update files. The video below should explain it.
Firstly, the error encountered is particulatly interesting. However, what's even more interesting is the screen that flickers up for about 1/4 of a second upon rebooting after the failed upgrade. It happens at about 01:19:32 in the video timeline:
I managed to catch a screenshot of the screen flicker (sorry if its dark):
Is this anything of interest?