Russell Simmons was always guilt ridden over the fact that he was unsuccessful in trying to get RUN DMC out of their Profile Records "slave deal" and over to the house which they help build which was DEF JAM RECORDS....
along with the fact that both him and his brother Run never did right by JMJ because the original contracts which never were revised didn't fully compensate JMJ as an official member of RUN DMC, because they were originally written with the intent of compensating RUN DMC's first deejay DAVEY DMX.....
another obstacle blocking the transition of RUN DMC to the DEF JAM label was the fact that Rush Management during the early part of Run Dmc's career had to share it's responsibilities and revenue with that other "silent" owner of RUN DMC being Richard Walters son of Mafioso affiliate and super agent i.e (erib b. rakim, paula Abdul) Norby Walters.
Lyor was at the time a young protégé of Richard Walters working the LA scene as a club promoter when a failed booking of a RUN DMC gig led to a falling out between both parties, to mediate the affair , Lyor offered his services to Russell Simmons and RUSH as compensation for it's loss. simply because RUSH wasn't going to be able to win this battle (full control of RUN DMC , and getting RUN DMC off of PROFILE) due to the fact the Walters had Gambino mobster and record company goon Sonny Franzese as it's muscle.
and the rest you know is history..Lyor goes to work for RUSH , Run Dmc continued their careers on Profile and Russell was able to walk away without sleeping with the fishes.