Paul McCartney is a fair drummer - check out 'The Ballad Of John And Yoko' which is credited as The Beatles, but is actually mainly John and Paul. John played lead and rhythm guitar, Paul played bass piano, maracas and drums, and both sang the vocals.
Lennon wanted to get the song recorded - about his marriage to Yoko and the subsequent press interest. George was in India (I think) and Ringo was away on location filming 'The Magic Christian' with Peter Sellars, so the two went in and did it, and pretty damned fabulous it is too!