Spielberg Scandals
I know that Spielberg was mad that the editor of Jaws got credit for saving the film and he (and Richard Dreyfus) helped reshape the legend that gave himself all the credit. He did the same thing with Duel, acting as if he hired Dennis Weaver when in fact Weaver was the tv star who chose Spielberg. Jaws owes much to John Williams score as well as Robert Shaw who was a writer in his own right.
JJ Abrams even said Spielberg came up with the "you are going to need a bigger boat" line even though it was attributed to Scheider as an ad-lib.
The story for ET was said to have come from Spielberg but years later it was revealed the idea was similar to a script circulated in Hollywood by Satyajit Ray.
Similarly he and Lucas got credit for creating Indiana Jones even though the character is cut and pasted with very little changes from Secret of the Incas.
Many know about his problems with Poltergeist--not just the Hooper situation but the fact that the script came from someone who sued and got a settlement (though his career went kaput afterwards).
There's also the Twilight Zone set deaths which are blamed on Landis for good reason, but Spielberg was the one who hired Landis.
Some others who may have faced career problems because of Spielberg...
Sean Young said she was up for a part in a movie in the early 80s, but because she rejected the advances of a movie mogul, he tried to destroy her career.
What films was she up for but never got? One of them was the Marion role in Raiders.
Many years later, she was asked what an actress could do to get a career in Hollywood and she replied: "sleep with Spielberg?"
John Carpenter. It is assumed that the Thing died at the box office because everyone loved ET, but one has to wonder if Spielberg and studio friends may have done something to kill the rival alien film. Lack of advertising? Hard to be sure, I thought it interesting though that Carpenter did Starman which was said to be a project that the studio picked over ET.
Then there is Big Trouble in Little China which seems to have ended Carpenter's luck with the big studios---it was expected to be an Indiana Jones-style film. Not saying Spielberg did anything, but he did interfere with the distribution of
Paul Verhoeven's Starship Troopers, which was supposed to be a summer release, but Spielberg used his influence to have it pushed to Fall so as not to compete with Men in Black.
How many other filmmakers used their influence to harm the career of another filmmaker?