While working on "Heavy Traffic", Bakshi received a call from Krantz, who questioned him about "Harlem Nights". Bakshi told Krantz: "I can't talk about that" and hung up. The next day, Krantz locked Bakshi out of the studio, reportedly tapping Bakshi's phone because he was wary of his loyalty as an employee. After Krantz fired Bakshi, he began to seek a replacement director for "Heavy Traffic", calling several directors, including Chuck Jones. Arkoff threatened to pull the film's budget unless Krantz rehired Bakshi, who returned a week later. During the film's production, Krantz attempted to maintain some level of control by issuing memos to Bakshi and other artists requesting various changes. John Sparey remembers being issued a memo asking Sparey to stop posting caricatures of Krantz on the middle of his door.