Monacello, however, is still angry - angry at his former mob bosses, angry at jurors who after two racketeering conspiracy trials chose not to convict Ligambi and Borgesi, and angry at the U.S. Attorney's Office, which, he says, has allowed two dangerous men to return to the streets.
But as he explained in interviews over two days from his South Jersey beach home, he's not sorry for the role he played in the process.
Throughout, he echoed many of the same accusations he lobbed from the witness stand and threw in a few more for good measure. All the while, he displayed the same bravado that prompted Borgesi's attorney, Christopher Warren, to once call him an "egomaniacal blowhard."
"I would like to personally thank [U.S. Attorney] Zane [David Memeger] and the jurors who let Joe Ligambi go," Monacello said Wednesday with obvious sarcasm. "Not only do I never have to deal with these guys, I never have to take the witness stand again."
Monacello, 47, testified in two trials against his former mob friends.
Jurors in the first go-round in 2013 found Borgesi not guilty of 13 of the 14 counts against him and acquitted Ligambi of five of his nine.
The second trial, which ended in a mistrial Friday, left Borgesi cleared of one racketeering conspiracy count and jurors unable to reach a unanimous verdict on three other counts facing Ligambi.
In both trials, much of the government's case hung on Monacello's word.
During four days on the stand late last year, he told jurors he ran a lucrative illegal gambling and loan-sharking operation for his capo, Borgesi, while the man served a federal prison sentence for racketeering in an unrelated case.
For seven years, Monacello testified, he delivered up to $40,000 in proceeds a year through deposits to Borgesi's prison commissary account or cash-stuffed envelopes left in the car glove box of Borgesi's wife, Alyson.
All the while, he said, he fought off interference from other mobsters eager to horn in on his business, and Borgesi's jealous brother Anthony - a man Monacello described Wednesday as "Fredo on steroids," a reference to the weak-willed Corleone brother in the Godfather saga.
The Borgesis and Ligambi did not return calls for comment.
But for all Monacello's bluster, it's easy to see what prosecutors saw in him as a potential witness.
He speaks authoritatively. He is frank and direct about his own crimes.
"We're all criminals. We've all done some bad things, but I've never murdered anyone," he said.
Most importantly, his tales, if believed, tied Borgesi directly to violent acts of mob retribution.
Jurors, however, just didn't buy it.
Asked to sum up her opinion of Monacello on Wednesday, one juror who asked not to be named, needed only a word: "slimeball."
"He clearly had so much pent-up hatred for Joe and George," she said, "it was hard to believe anything he said."
For example, she said, Monacello testified that he once witnessed Borgesi fly into a rage and bite a chunk out of mob associate Angelo Lutz's forehead during a bachelor party. Defense attorneys later showed wedding photos, shot a day later, where lutz appeared smiling, without a scratch.
But Monacello said he remains unconcerned with what anyone else thinks. He has his eyes on the future.
Since his release from federal custody, he has worked as a regional director for ACN Inc., a multilevel marketing company. In that time, he is quick to note, he has received multiple promotions.
What's more, he is convinced the government isn't through with his former mob colleagues.
The recent arrests of mob associate Ron Galati, on charges he hired men to kill witnesses in an unrelated case, and Anthony Nicodemo, a made man accused in a 2012 slaying, could unearth evidence of past crimes, should the men decide to cooperate, Monacello said.
"The best part," he added, "is that it won't include me at all."
Still, he faces his own sentencing this year in the same case that scooped up Ligambi and Borgesi.
But as he mulled over his prospects from his dining room table, Monacello maintained that neither prison nor the threat of gangland retribution scared him.
Until then, he said, "Tell them I'm relaxing at the beach."