One of the more common explanations pegs the song in question as "Can You Please Crawl Out Your Window?" See, for example, Wikipedia's summary:
Dylan played the song to Phil Ochs as the two were riding in a limousine. When Ochs expressed a lukewarm feeling about the piece, Dylan kicked him out of the limousine, yelling "You're not a folk singer. You're a journalist."The song, in fact, was not played in the car, and it was in fact another song recorded at the same session in 1965: "One of Us Must Know (Sooner or Later)." This was explained by Ochs to Rolling Stone and to author Marc Eliot (who included the anecdote in his revised outro to Death of a Rebel). The story as usually told at least captures the sentiment correctly: Ochs felt that Dylan was losing his songwriting clarity in the material recorded for Blonde On Blonde, and Dylan felt that Ochs' writing on political matters was "bullshit," and that only expressions of a personal nature mattered (this was a change, of course, from his early embrace of topical songwriting).
Undoubtedly Ochs didn't mind being called a journalist (his early shows billed him as the "singing journalist") but he remarked that it was upsetting to hear his idol (Dylan) saying that his songwriting efforts were in vain. The two wouldn't reconcile for nearly another ten years, with Ochs inviting Dylan to the benefit concert An Evening with Salvador Allende in 1974. Ochs also made a brief appearance in Dylan's film Renaldo & Clara, where he takes Dylan's hat before playing a set at Gerde's Folk City, which included his only serious cover of a Dylan song, "Lay Down Your Weary Tune." Somewhat aptly as a metaphor for their relationship, the concert footage cuts just as Ochs begins playing in what became the last film shot of him before his death.