I also voted for your neighbours' driveway lights.
I believe to see the top of your terrace railing at the bottom of the picture. This excludes Cody as a possibility because you should see a shadow of his body if he were leaning over the railing (this, and I think Cody was ducking and hiding somewhere during the whole storm, and not being outside).
I also rule out everything supernatural because it simply doesn't exist period.
I guess it could also be the very last glow of a flash, but I'll stick with the lamps.