I think of it like Trump used to be an admirer of the Clintons - he was totally unaware of the criminal and treasonous dealings going on, funneling billions of govt dollars and special interest contracts into their charitable foundation. No doubt he would've seen the likes of documentaries such as Clinton Cash
https://www.youtube.com/watch?v=7LYRUOd_QoM and couple this with the email scandal, Benghazi, and the 'Clinton Hit List' and his eyes would've been immediately widened open.
Just like the Clintons spent decades ripping the people of the USA off with their racketeering tag team act, Klein did exactly the same to the Beatles and the Stones.
Sometimes the worst criminals get away with their crimes because they can get away with it before everybody's eyes - including those closest to them. Remember when the Lostprophets lead singer Ian Watkins was convicted for child rape and a host of disgusting offences - his fellow band members were completely unaware of his secret life.
Jimi Hendrix is another interesting case. His manager Michael Jeffery was a very dodgy character and had just signed a life insurance deal where he became the sole beneficiary of a $2 million policy in the event of Jimi's death. Reports say that Hendrix was onto him and trying to cut him loose, and when Hendrix died he was found to have more wine in his stomach than his gullet could naturally ingest - in other words, someone 'drowned' him by forcing wine down his throat while another person held him down, and then made it look like an overdose. Karma came for Jeffery though as he was killed in a plane crash just a couple of years later.
History is littered with dodgy corrupt characters - the sad thing is, history often writes them as heroes and fine upstanding citizens.