a couple of times I’ve accidentally hit the P key while in object mode. It changes the image completely, locks Blender and I cant recover from it and end up ending blender to exit. Is there a way to back out of it?
Huh…P is the magic key for the game engine freaks ( like me)! 
Why want you to go out?! Well, try ESC key?
OTO, thanks. And I want to go out because I’m trying to model a building, not play a game. 