You can't infer anything about his motives from the number of files he took. It's just good sysadmin instinct to backup everything, encrypt it, and then sort it

You can't infer anything about his motives from the number of files he took. It's just good sysadmin instinct to backup everything, encrypt it, and then sort it out later. Disk space is cheap and it's better to have too much than be missing something important. It also often takes less effort to take more data simply because it requires no additional thinking or typing to exclude things.