I think it was looked at that the Dellacroce was behind the hit.
Remember the family was divided into to.
Dellacroce faction had the Blue Collar/Street Guys/Shooters and Castellano had the White Collar/Money Makers

The only crew that Paul had that could do work was Demeo, who he had whacked and let two of the heavy hitters go with Gas.

Essentially, he had no BITE.

More importantly most guys in the family felt they weren't earning enough that what matters the most to these guys anyway, the MIGHTY DOLLAR.

As for Chin, I said this before he is made to be the real boss of BOSSES, and that Gotit was afraid of him, etc.

However, he had his whole Borgata, the whole Commision behind him and guys inside the Gambino, family that wanted REVENGE

Gotti, never hid a day after the hit.

Why not send a few carloads to the Bergin where Gotti and his whole crew were every day?

Or when he was driving from his house to the Bergin.

Or when he was driving from the Bergin to the Rivenite?

Yeah so, they would have killed more than just Gotti, isn't that a pretty good message to deter anyone from looking for revenge?

Or....?

Instead, he was in on breaking a commission rule of using a bomb which was a no no.

When Gotti, wanted to Kill Castellano, he sent shooters and back up shooters, back up shooters for the backups.
When Persico, wanted to Kill Scopo, he sent shooters, backups, and more backups.

The way the Chin handled Gotti, by farming it out to Gas Pipe was almost like he was the one that was scared.

The boss of BOSSES, farms out a murder contract without signing his name to it.