That's what asset versioning is for. I can't believe they don't concatenate their assets. Even their versioned PNG files use Etags... With proper caching and other optimizations they could probably get their site load times down to maybe 300ms (almost instantly) instead of 1.8s and at the same time fix such caching problems.
Apple's website has a long history of being superficially pretty, but seriously lacking when it comes to any form of professional usability.
To wit, it is typical of over-designed sites in that it is fragile when people use it at different resolutions, on different browsers or in different countries (e.g. when the iPhone came out, or rather didn't come out different international versions of the page had rendering issues because the big chunk of space for the iPhone wasn't there, and all of a sudden all the pretty little lines didn't line up.
Then there's the way they were so fond of grey-on-grey text - who's idea of usability is that? Put your hands up so you can be slapped. Repeat after me: "contrast is good, m'kay?".
