The Beatles and Brian were allegedly tricked into signing a slave?
The question contains false assumptions. There was no slave contract, it was a music publishing contract There was no trickery, the contract was legal and in writing and had been requested by Brian Epstein. The relationship was amiable until James sold Northern Songs in 1969 without offering Lennon and McCartney an opportunity to buy control of the publishing company. They never again had the rights to their own songs.