Board Thread:Lore Discussion/@comment-2165692-20140425203121/@comment-16669347-20140924082838

The Falmer's helmet isn't a bug, but it's not a hint either. You can see out of the Falmer helmet for the same reason Khajiit's tails go through armor or that clothes magically change into different versions for different genders. Because it's a game and as such some things are going to happen for convenience.

The timeline thing is because bad writing, TES is full of such mistakes and discrepencies.