I personally think Stanfa was involved despite some sources saying he was picked at random to drive Bruno home that night. I just think the fact that he was seen at the hospital conversing secretly with all of the conspirators plus the fact that the Feds have surveillance photos of him up in Newark & NYC with the conspirators literally in the days after the assassination. It's just too much of a coincidence for me... I think he was another case similar to Casella and the Genovese where Stanfa's connections to the NY Gambinos were simply too strong and as such saved his life and got him a pass. On a slightly related note, without knowing the exact traditional LCN rule on this situation, I think that his likely role in that assassination plot further legitimized the Merlino/Ciancaglini/Young Turk rebellion against Stanfa with Stanfa being a key piece of the plot to take down a boss, which ultimately led to the destabilizing and violence of the Philly Family throughout the 80s and early 90s.