"Mr. Stone was sentenced to spend 40 months in prison until he got his reward for keeping his lips sealed," Weissman continues, of Trump's decision last week to commute his former adviser's jail sentence.
Weissman is an attorney who played a key role in the Mueller probe. On Tuesday it was announced that he would be publishing an insider's account of the investigation in September.
Trump's decision last week to spare Stone jail time attracted widespread criticism from both political parties. Sen. Mitt Romney, an outspoken Republican,described it as an act of " unprecedented, historic corruption ."
The president on Monday defended his decision to commute Stone's sentence, and claimed: "I am getting rave reviews for what I did for Roger Stone."
Stone, a veteran "dirty trickster" and GOP strategist, was found guilty of lying about his contact with WikiLeaks during the 2016 election.
The site published thousands of emails stolen from Democrat servers in a bid to discredit Trump's opponent, Hillary Clinton, that US intelligence later found had been stolen by Russian intelligence.
In his first TV interview since the commutation, Stone told Fox News' Sean Hannity Monday that Trump had effectively saved his life.
"I was literally hours away from being sent to a COVID-infested prison in violation of the current Bureau of Prisons and DOJ [Department of Justice] policies," he said.
He also claimed that a lung condition meant a coronavirus infection could have been fatal for him.
Stone went on to allege that the trial was unfair: "I had a biased judge. I had a stacked jury. I had a corrupt jury forewoman ... My trial was over before it started."
In the interview he responded to claims that the commutation was a reward for his silence, claiming he has refused to lie to frame Trump.
"There was no circumstance under which I would bear false witness against the president," he said. "I was just not willing to lie ... What I said has been consistent, that I would not lie against my friend of 40 years [Trump] so they could use it for impeachment."
On Saturday, Mueller also wrote a rare op-ed in The Washington Post defending his probe against claims made by Trump and his allies that it was politically motivated.
"Stone was prosecuted and convicted because he committed federal crimes. He remains a convicted felon, and rightly so," Mueller wrote.
Weissman, in his op-ed, called for Attorney William Barr who has said he did not back the commutation of Stone's sentence to call Stone before a grand jury to establish what really happened back in 2016.
"If there was nothing nefarious about his coordination efforts, why did he lie about them to Congress? This question remains unanswered, as the Mueller report notes," Weissman wrote, of Stone.