No it is all the way through. The way the L bracket sits it is not possible to get the nut in the back on. If the screw was two inches longer then you could, so I think there has to be some trick to getting it on.
I am doing this with the side cladding on, I did not want to go through taking off cladding, maybe you have to take off cladding so you can get behind the area and put nut on.