Engineering 101: Spouting convincing bullshit.

I'd certainly defer to someone with military experience on this one, but since Buzzkill hasn't swung by I'm going with basic fracture mechanics. The real telltale is the bricks on the corner. There's only a few columns of bricks missing on the "right" wall, while the "left" wall is missing many columns. Think of how the "boom" would "move". The "right" wall would see a largely perpendicular push. Brick walls resist that sort of load fairly well as their own weight helps keep the bottom in place and you've got the structure behind it. The "left" wall would see a 45 degree push from the back side (coming around the corner). That's bad because there's no back support in that direction and mortar doesn't do well in torsion (twisting). So you end up peeling the corner out into the street.