What's under scrutiny here is their acknowledged mutual fascination, the attraction that complicated their hours and times, the complications of the times in which they lived that filtered their desires and possibilities. Did they or didn't they is merely conjecture. Could they or couldn't they is more precisely the question. Nuance is the language spoken in this movie. Its credibility is assisted by the strength of the actors.
Hart believably captures Lennon's accent, gestures, wit and star power.
We can also see aspects of the same street-smart piece of rough trade that must have appealed to Epstein. We know the future, though these characters do not. Thus, it's sobering when the movie shows Epstein and Lennon making a pact that no matter what courses their lives might take, they would meet again in Barcelona ten years hence. That would be in 1973. By then Epstein would be dead and the Beatles would have ceased as a group.