You think the band broke up because of one woman and not the culmination of numerous reasons the band themselves have stated?
Paul McCartney himself said that Yoko had nothing to with the disbanding. But sure, it's true.
Exactly. If you want proof, just listen to the music. Early albums: lots of collaboration, many songs with everyone singing together. Later albums: everyone works on separate songs, all have their own distinct style, bringing in outside artists (i.e. Eric Clapton). Besides, John Lennon was a big enough asshole that he could break up any band without any help.
Now that's true; Lennon had quite the superiority complex - and yes Yoko did have a part, but Ringo was quite the 'sensitive dude', took offence all the time, George was so pissed that Lennon downplayed his contribution all the time etc etc.
Paul McCartney himself said that Yoko had nothing to with the disbanding. But sure, it's true.