When I come to shut down I often use Alfred to "Quit All Applications" then the "Shut Down." I do this at the end of each day.
I sported this bug, sometimes if you "Quit all" and "shut down" before all the apps have closed, my computer reboots and displays a message "Your computer had to restart because of a problem."
I have noticed this nearly always happens when I tell Alfred to quit all, then shut down straight after. And because it sometimes takes a long time for all applications to close (usually an adobe program that just takes ages to quit), if I force quite the apps that are taking a while, then the mac shuts down, but the reboots instantly with the error message.
Because I noticed this I have been telling Alfred to Quit all, and waiting a while for all the apps to close in their own time. Then I would Tell Alfred to shut down. This usually works, but occasionally the computer restarts and still tells me "Your computer had to restart because of a problem." Just thought I'd let you know as you might be able to fix it.
Apart from that Alfred has been running great, it's one of my favourite apps!