So basically Bauer is saying that Zodiac made a bazillion mistakes in the 340 which gives him the liberty to make anything fit
His effort is clearly not correct. The 408 had mistakes but even those were logical. Like a few mispelled words or missing one word out entirely, probably by accident. However 90%+ of it was perfectly correct and could be deciphered using consistent logic. Craig breaks every rule in the book and his method gets worse as the lines go by. It's no different than what others have done before and claimed to be correct.
My guess is the 340 is either a fake to waste police time. Or it isn't a homophonic substitution cipher like the 408 and requires a different angle of approach. It would make sense for Zodiac to look at his 'Crypto for noobs' book and try a different method. I would expect there to be a message in the majority of the text if any at all, similar to the 408, not just the top few lines.