To be fair, William Cheung should be in the Guinness Book of Records for the number of instructor level students having defected from him over close to five decades. They are legion.Just a btw but a Serbian TWC master and 300 strong group all defected to pb recently. For the same reasons. : )
I know a significant number - the first having busted up with him in the late 1960s. By all accounts he was never an easy man to work for or get along with. I've witnessed this first hand and seen and heard tons of hearsay.
I'm glad this was just a BTW and you weren't trying to score a point for pb or anything