Walt can't not find out next season about why the planes crashed. He'll put two and two together pretty damn quickly. A google search or two. He'll find that he was responsible. The darkness will continue.
edit: and to all the naysayers about "coincidences." I think people might forget just how many darn "coincidences" are happy to occur in this show. Walt meeting Jesse comes to mind. I find no lack of suspenension of disbelief here, it's just how this show is, practically every episode relies on one coincidence or another. To some people the writers may have went slightly too far, but in the end it's nothing.
HEADLINE: Flight control man responsible for midair airline crash. Wow.
edit: and to all the naysayers about "coincidences." I think people might forget just how many darn "coincidences" are happy to occur in this show. Walt meeting Jesse comes to mind. I find no lack of suspenension of disbelief here, it's just how this show is, practically every episode relies on one coincidence or another. To some people the writers may have went slightly too far, but in the end it's nothing.
HEADLINE: Flight control man responsible for midair airline crash. Wow.