Disowned Adaptation: Akira Toriyama first showed what could be read as professionally polite disappointment over the film, stating that it should be taken as an "alternate universe" Dragonball. However, after the film was released and by the time of the Battle of the Gods movie, he had since clarified his stance. He stated that although he had offered advice to the crew on how to adapt the series, they had never listened to him, and thus the finished product was a disaster and something he could not see as anything "Dragonball" at all.
Executive Meddling: Many of the changes were presumably added in due to Fox's meddling, especially considering their track record in other films. We'll never know how much was dictated to be there, and how much the writers came up with themselves though. One of the particularly nasty changes they wanted? To make Piccolo a Bishounen. James Marsters would not have this and demanded he'd be like the original.
Promoted Fanboy: James Marsters referred to the anime as "the coolest television cartoon in the last 50,000 years."
This is a unique case. Marsters watched the anime after getting the role of Piccolo in order the study the character.
What Could Have Been: The original script mentioned under They Just Didn't Care was apparently a much more faithful adaptation of the series. But once it was out of the scriptmaker's hands, changes were made.
Emmy Rossum was originally going to wear a short blue wig as Bulma, but it was ditched after a costume test as both she and the director hated how it looked. A pink wig was also said to have been tested.