A source close to Respawn Entertainment has told Vanity Fair (via Superannuation) that "revelations" about Jason West's behavior upset Vince Zampella, leading to a rift between the longtime colleagues and Call of Duty creators.
"Vince felt that Jason was sabotaging the company," a source said.
Speaking with Vanity Fair in April, Zampella would not go further into detail regarding the nature of his relationship with West, only saying, "It's hard to work with one person for 15 years."
A Respawn Entertainment representative told GameSpot today, "All the comment we have is what is already in the article. Vince put out an official statement about Jason leaving on our blog a few months ago and that's all I got for you."
It does not appear West will return to the industry anytime soon, telling Vanity Fair in August that he is "soured" on the game business, due in part to being "strong-armed" by executives.
"It does sort of sour you on the industry," West said. "It's tough. If we can't get treated well, what possible chance does a newcomer have? How do they prevent themselves from being strong-armed by the guys with the money? I wish I had the answer to that question, but I don't."
West and Zampella formed Respawn Entertainment in early 2010, following the pair's split from Infinity Ward and Activision over claims of broken promises and an internal investigation, which eventually led to a lawsuit against Activision.
The case was settled before going to trial in May last year.
Respawn's new game, Titanfall, launches next year exclusively on the Xbox 360, Xbox One, and PC.