Well, they didn't, and you have to click through "i understand" (or whatever) to see the contents from servers with expired certs. Usually you need files from them and not vice-versa, sp as far as they're concerned, it's your problem now.
I guess it depends on the country. Where I live they’d be on the hook in somehow safely providing me with the files if they were involved in me fulfilling some kind of legal obligation to them, and I’d be off the hook if they refused.
