You're right, of course. No matter if it was the actual reason for the error messages you got, knowing about the case sensitivity stuff is an improvement. I'll definitely keep that in mind going forward and make doubly sure to not change any file name casing halfway through. So, thanks for teaching me about that. :)
About the error itself: Don't worry about it too much - these things happen. Maybe something got jumbled while unzipping the patch, who knows.
The important part is that it's fixed now and works. :)