Well parts of it were taken from apparently truth. In an interview somewhere I can't remember, Paul did say that he was with John that night watch Saturday Night Live and they really did consider going down to the studio.
I was watching it live that night too, would have been some kind of surprise to say the least.
I too thought it got a bit imaginative but it was done pretty well as far as getting in facts, it was believable even though it could not have been what could or would have happened but the thoughts of a writer, he did a good job.
I really thought the fan reactions were done quite realistically, with the exception on how long it took them to recognize Paul as his face was all over the media for years, much more than John. That was kind of unbelievable. Going up and talking to John and not realizing that Paul was right there.
Adrian Quinn did an ok job as Paul but I won't go into the critiques of the visual and vocal weaknesses of the movie. The actors and the whole production actually did make you feel you were in that room with Paul and John.