Well the video was removed for copyright infringement before I could see it. Sure, the straight blast works on a retreating opponent. Sometimes it works on an opponent who is pressuring forward, but weakly. However, be all end all, hardly. Also Andy, there is a difference in what is called a straight blast and a boxing blast. The latter taking the place of the former in the JKD curriculum.
"When I let Go of who I am, I become who I might be."
Lao Tzu