I suppose that if you believe in God then you'll find so-called proof anywhere, because you believe in the first place. How you could explain to an atheist that the Beatles are ''proof'' of his existence though is more difficult.
The only way I can think of how anyone would come to have faith in God through the Beatles is through George, in this case the Hindi gods. But as the majority of Hindus are so because of them being taught it from birth by their family, I wouldn't have thought this scenario to be all that common.