Good luck with that. Spanky and I couldn't even replicate the bug. It's difficult to fix something you can't see happen.
Exactly. I have never heard of this roof bug in all my time of playing this game. Never. I'd like to see a video or something, because the only information I have is "roof bug."
My best guess is that what people are referring to is that in this version of the game, the first-person eye level is higher than the third-person eye level. This means that, in some cases, you can go prone, peek over an edge, and no one can see you. It's a situation where you can fire on someone and they cannot hit you. There is a spot like this North Outside in Pipeline looking toward the west entrance.
If this is the "roof bug," then messing with the roof will solve nothing, because it's an element of the game and can happen in plenty of other places.