Was this a local IT type who thought he/she knew what they were doing a royally screwed the pooch?
Was this someone acting on verbal orders to make sure information on there was unrecoverable - to protect other sleepers?
Was this intentional, so that they could push for even weaker encryption and/or deeper, more comprehensive holes in the security. As in "Look, existing capabilities aren't enough, a simple mistake can deny law enforcement all this critical information..."
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