Bernoulli's equation and window panes

Hi!
I've been solving problems that apply Bernoulli's equations in *reasonable* situations.
One comes from Serway's book. It applies the equation for the force exerted on a window pane in a stormy day. They give us the speed of the wind blowing outside, the area of the window pane, the hint that it's going horizontally and that the inside pressure is about the atmospheric.

Solving this problem as if the air went along a stream line *through* the windowpane is what really troubles me. I can't imagine how the equation should be a reasonable approximation to create this textbook problem. The book even goes on to mention a real life incident about a skyscraper that had its windowpanes falling out because of bad design as an example of Bernoulli's equation in action.

We all know that Bernoulli's equation is valid only for a stream line and the windowpane is blocking it, it can't be right. Is there any way to justify why even the solution manual for instructors explicitly states to take points 1 and 2 in the air just inside and outside the window pane??? Any thoughts? thanks