I've just been reading the threads and haven't found anything that conclusively debunks this theory. From what I understand, this theory is just as likely as the hijacking one (both have holes that don't quite fit given the current evidence).
Also Goodfellow's theory becomes even more unlikely if it's true that the programmed change in direction occurred 12 minutes before sign off[1].
Either way the speculation run amok from the U.S. media, namely CNN's television coverage, is atrocious.
[1] http://www.cnn.com/2014/03/18/world/asia/malaysia-airlines-p...