CB is right, the verticals where corrected in camera with shift. I also shoot all of my still life and beverage with my tech camera and use shift and tilt/swing is every single image there, even if it does not look like it.
Now, I do usually fine tune the images using the tools in C1 just to make everything perfect, but I never use C1 to do any major fixes. This is because C1 assumes the center of the image circle of the lens is the center of the image, as does Photoshop, so the corrections are applied equally the same depending on the distance from the center. If the image had been shifted in camera though, this correction does not apply an accurate fix.
In this image, you can imagine the lines at the top need to be skewed more then the lines at the bottom, due to shift. So to accomplish this, I will create a file that is 36x48 inches (4 times the size of my P45+ files) and layer/position the image so the IC center is dead center the image file. After this, I can use the PS tool to correct the perspective and get an accurate correction.
I would like to note that I very rarely ever do this and almost always correct everything in camera. Here, I thought, the ceiling tiles would not be a big deal, but, in studio when I had more time to think, I felt I was wrong. Also, this is the very last step. If I need to layer something else in, I will do so with the uncorrected file and correct it again. Since it is not a very precise method, it is impossible to correct an image to exactly match and line up.