Today I was upgrading a nexus 5596 and it just died on me when it rebooted. When it did, I started researching it and guess what: there’s a severity Catastrophic bug for this:
I thought the switch was dead… but it came back (with the new system version!) after six hours. Just like that. Amazing, isn’t it?
I came across one forum entry where the nexus took 3 days to come back.