To a large extent, the groundwork was laid in 1766 when the decision was made to put the University in the NYC market. The market was pretty much all the B10 was looking for. (In the press conference announcing Rutgers, Delany was so unconcerned about Rutgers' specifics, that he didn't even realize that Rutgers had recently expanded the Stadium.)
More recently, credit would go to the 2006 season, especially the pressure put on local cable companies and the NFL Network to ensure local fans could watch the Texas Bowl. That showed that the Rutgers fan base could influence cable companies, something that was needed for the BTN.
But that is not to say that Pernetti did nothing. Delany indicated that he and Pernetti were in continual communication since the Nebraska expansion. Pernetti had often commented that Rutgers would end up in a good spot, so he seemed to know that Rutgers would be selected for the B10. And Pernetti kept the school from panicking while conference realignment was going on elsewhere. (While you could characterize the Flood hire as a panicked move, it was more panicking about signing day than about being left in the BE.)
I think it is fairly obvious that Rutgers would have been invited to the Big Ten, regardless of who was AD or President, since the invitation was driven by the B10's desire for large eastern markets. But I think there is ample evidence that Pernetti did much more than just answer the phone one morning.