Interesting Counter Argument

I remembered today that a plane flew into the White House a few years ago. It occured to me that this would be an interesting counter argument to some of our 9/11 statements.

"September 12, 1994: A man, flying a stolen Cessna airplane, entered the prohibited airspace around the White House just before 2 a.m. After passing over the Ellipse, the man, identified as Frank Eugene Corder, crashed on the lawn just south of the Executive Mansion. The plane struck a tree near the South Portico steps and hit a corner on the first floor of the White House. President Clinton and his family were not in the residence at the time. Corder was killed in the crash."

http://archives.cnn.com/2001/ALLPOLI....incidents.02/

Now, knowing this, what would you say if someone said this to you...

"You people always talk about how P-56 is the most secure airspace in the world. That they have the best radar systems money can buy. Well, on September 12th, 1994, a plane hit the White House. Explain that..."

How would you respond to this? I know how I would...