Most likely this was some local net issue, because pool was definitely up whole time. I'm using online monitoring from three continents (Europe, America, Asia), I usually receive a sms after one minute of unavailability and I didn't received any report. I was also online during the time and pool was running fine.
bitcoin.cz site is hosted in another country than the pool.
I think you are more likely to be right than I am, having more diagnostics data, experience etc. So I think we'll call it a local issue. I still find it damn odd that it would fail from a network close to the back-bone and from a well-established corporate network at the same time. If you are curious, for some reason, feel free to PM me since I won't disclose the locations and providers on a public forum.