Yeah, I got that.... You're hoping that "unpatching" will fix the glitch instead of starting a fresh game and getting back to the same point.
My point, initially, was that, if you had BOTH drm rights to yourself (your console AND your gamertag), you could theoretically just delete cache on your own system, reload your save *offline* and re-download the patch *after* the glitch area was solved.
Being that you don't have "original console" DRM on your own system then you can't play offline (which you know) and thus, whenever you load the game you'll either have to be online with your GT which will force the patch download, or else be stuck with a trial of the game (which I think you were pointing to saying you can't do and would have to take it to your brother's console). /Ramble
Phew. That was too much detail for such a simple, well-intentioned misunderstanding.
Yup, sounds like you knew what I meant. I did end up going to my brother's house to fix it. I played a few minutes, got out of that area, saved, and it loaded just fine at home. Hoping to complete it tonight or tomorrow if I'm lucky. Just a few sections left to complete.