Someone else's feelings aren't evidence though. Anthony Colombo may feel whatever way he wants about this, that or the other thing - just because he was the victim's son doesn't give him any greater insight into who committed the crime - as a matter of fact, it presents the very real risk that he is too close to the subject matter to review it objectively and is too prone to confirmation bias.

Alphonse D'Arco wrote in his book about how he and fellow mobsters believed the FBI had the power to give them cancer. That's an absurd thought (at least I think so). It's a perfect example of just how somebody can believe something without it having any basis in fact.

It's not like we don't know who actually shot Colombo - what was Jerome Johnson's connection to the government? Would the government really get involved with a low level thug like that and trust him to carry out a mission of such importance to them? (And why would it have been that important in the first place to kill Joe Colombo? His league may well have been a pain in the ass, but at that time was it any worse than massive anti-Vietnam demonstrations or the Black Panthers, for example?)

Also - when Johnson failed to actually kill Colombo, why was another agent not dispatched to finish the job in case Colombo somehow came out of his coma?

And with Colombo then out of the way, who did kill Gallo subsequently? Everyone likes to lay a claim of responsibility to it but nobody for sure seems to know who did it, much like the murder of Colombo himself as you've pointed out.

Joe Colombo was involved in the underworld and ergo by definition had countless enemies. It is not a great leap to suggest that a mob boss' life is always somewhat in danger. From Masseria to Anastasia to Galante to Castellano that is a known occupational hazard of that life.

If the government had wanted him dead that badly and could succeed so easily in doing so without leaving the slightest bit of evidence....then how did they fail to convict John Gotti over and over? For that matter why did they not simply kill him too? Incidentally...I think Gotti had the deck stacked against him in his last trial - the DA with the FBI didn't fight a completely fair fight but they certainly didn't arrange for his death.