In Blood Covenant, Michael Franzese says in 1975 "Jo Jo introduced me to Colombo family acting boss Thomas DiBella" and that DiBella was put there by the real boss Persico.

I'd assume that if the Commission was voting to have someone killed, Persico would have to actually send out his vote from prison and not let DiBella decide the Colombo vote for him. Fred DeChristopher, whose house Persico was hiding out in later on, testified that Persico voted against killing Galante. Even if he was opposed to it, I'd assume legally he was involved in the murder. However, the legitimacy of DeChristopher's testimony is worth questioning.

Also, it doesn't seem like the Galante hit was Commission business anyway. He wasn't the boss, Rastelli was. So there was no need for a Commission vote to take him out. Pmac mentioned earlier, Massino testified that Rastelli gave the order. If I remember correctly, it was all taken care of by Bonanno members. They did meet up and were congratulated at the Ravenite afterwards, but that only shows Bonanno and Gambino involvement, not necessarily the Commission.

Even if he isn't actually guilty of involvement in the Galante killing, and I'd bet he wasn't, Persico was still convicted of other charges in the Commission trial, so he might not get out of prison. Plus he's still got a few years to go from the Colombo Family trial convictions!