This is an impressive scene on Yamamoto's Death from "Isoroku Yamamoto" (2011) a Japanese World War II drama film about Isoroku Yamamoto. The plot of this scene is as follow: Admiral Isoroku Yamamoto and his team was trying to go back on Japan .. But they are surprised on US Air Force P 38 Lightning, shooting his Mitsubishi G4M Medium Bomber and Yamamoto's plane crashed..
A P-38 Lightning shoots Admiral Yamamoto's Mitsubishi G4M Medium Bomber and he received 2 shots of 0.50 caliber bullet wounds. The Japanese were not going to report his true condition. Bad for morale! Between the .50 cal hits and the plane crashing it would not be a pretty sight.
A possible interpretation of this scene is that Yamamoto's final moments resemble what his country was going trough. Carrying a death wound and facing inevitable end. The mushrooms cloud signals into to it. An accurate metaphor.