God, I'd hate to see you guys try to figure out the Halo or- God help us!- the Star Wars canon and continuity hierarchies.
Firstly, the assertion that there are oodles of standing inconsistencies in the Dragon Ball canon is trotted out all the time, but aside from the TV specials and movies, I've never actually found an error I couldn't explain in-universe, with only one exception. (IN the anime during the tail-end of the Buu debacle, Gohan, Piccolo and a few others are depicted in several places at once. Seems more like an animation error to me than a writing error, but it counts.) Care to list a few that you're thinking of? I'll shoot down those I can off the top of my head, and maybe you'll be the one who finally manages to stump me. (For the love of God, don't try to dredge up the number of people in the Room of Spirit and Time. I'm sick of explaining that one over and over again.)
Originally Posted by Volta
Most of the nonsense happenings of Dragon Ball aren't actually continuity errors, but just really dumb decisions characters make (or forget to make, in some cases), or the audience assuming (foolishly) that characters can't/don't lie or make mistakes.
Secondly, copyright law with respect to authors and their delineated creations (ie, characters, worlds, fictional technology, etc.) is much stronger and stranger (in spirit- I'm not as well versed on the letter of the law) in Japan than in the US, Canada and much of Europe. Basically, he has to be credited as they are still using his world/universe and his characters, and in some way he'd have to approve GT legally, if not canonically. Authors there retain full control over their characters and such-- which by the way makes most parodies and fan-fictions of anime and manga technically illegal, but not worth the cost of enforcement. (There's not quite an equivalent to fair-use exceptions in Japan, either.)
If it's hurting your head to think of this, consider that Michael Crichton is spared a brief nod in the credits of Jurassic Park 3, even though he only wrote the two books and co-wrote the first film, and the second and third films bear little to no resemblance to either of his books. Now, here, it's partly a licensing deal and an ethical avoidance of plagiarism, but there are stronger legal devices in Japan to force the same sort of credits. Toriyama did not write GT, but did write the source material (the Dragon Ball manga) and did allow TOEI to produce GT.
Finally, it you go look at the movies- most of which he had nothing to do with, beyond the existing universe and characters- you'll find that Toriyama is credited there, too, as the original author.
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
GT is canon within the anime-based continuity, but is not a canon material within the manga-based continuity. Though the anime is based upon manga, the two continuities are separate and distinct from one another.