It seems extremely unlikely that you could determine the problem from "the last thing I'd worked on", and it seems even more unlikely that a spreadsheet with (b

It seems extremely unlikely that you could determine the problem from "the last thing I'd worked on", and it seems even more unlikely that a spreadsheet with (barring any additional information from this story) account numbers and passwords would auto-trigger a shutdown: there would be so many false positives that most people would have had their accounts closed by now.