Novels aren't canon. As for other examples, I'm not sure if there were that many at the time they were making the movie. There was arguably Ben Finney (still not sure how a guy that nuts managed to hide for years), arguably Admiral Mark Jameson, Captain Maxwell, and Admiral Nora Satie.
Fully aware that "novels aren't canon", but I can tell you that Roddenberry did
get annoyed with the number of ST novel proposals and RPG materials that were involving the plotline of Starfleeters-gone-bad, to name a few off the top of my head: "Death's Angel", "Dreadnought!", "Battlestations!" and the cancelled "The Lost Years Saga: The War Virus". Diane Carey had a proposed third Piper novel canned, too, and a sequel duology, "The Federation Mutiny".
In TNG, there was also "Conspiracy".
If Roddenberry disliked the story enough, he might have asked that his name be removed from the credits.
That was always his threat, from ST II onwards; that if he did not approve his name would be withheld from the credits as a sign to the fans.
He was gravely ill at the time of ST VI but responded via memo to an early script, the one where he doubted the wisdom of making Saavik a traitor, and to Kirk's anti-Klingon attitude. He watched the work print in the Paramount theatrette from his wheelchair with his carer/chauffeur, Ernie Over, and was essentially taken straight to hospital. He never came home.
Rumours abounded that he "raced to his office" and started dashing off memos and making angry phone calls, but Ernie himself once told me that Roddenberry was too ill to do anything like that and GR's only
comment on ST VI that day was, "I'm sure the Star Trek fans will like it."