it may be some sort of function key on the keyboard that was pressed when leaning. I feel it would be strange for physical damage to cause the screen ti flip 90 degrees. I would say leaning on it is going to just damage it to where you see bad pixels or worse. Also try going in to your display settings and see if there is a command to adjust 90 degrees. You may be able to get to display properties by right clicking the desktop. Hope this helps.