I know this is pointless but....
Try something. Take a picture of a building straight on with the camera held perfectly level and not tilted either forward or backward. Then take a picture of the same building with the same camera/lens combination with the camera tilted upwards. I betcha a nickel you can see this same "distortion" in the second picture no matter what lens you use.
The only way you can avoid this is to always shoot pictures level and dead straight without any tilt. Or you can invest in a large format camera with full swings, tilts, rises and falls that allows for perspective control. (Thus my post about Sinar, Linhof, Deardorff, etc.)