Author Existence Failure: As a matter of point, the whistling on "(Sittin' On) The Dock of the Bay" was a placeholder; Redding intended to write another verse.
What Could Have Been: Died just before his music broke into the mainstream, at what is now regarded as a possible career turning point hinted at by "(Sittin' On) The Dock of the Bay". There is also evidence to suggest that "Dock of the Bay" was intended to be part of a Sgt. Pepper-style Concept Album.
Related to Redding's plane crash, both Steve Cropper and Stax session bassist Donald "Duck" Dunn were also supposed to be on that very flight, but they changed plans at the last minute.