Though the longest jail term to date in Robert Mueller’s probe, it could have been much worse for Paul Manafort.

US President Donald Trump‘s former campaign chairman has been sentenced to nearly four years in prison for tax and bank fraud related to his work advising Ukrainian politicians, much less than what was called for under sentencing guidelines.

Paul Manafort, sitting in a wheelchair as he deals with complications from gout, had no visible reaction on Thursday as he heard the 47-month prison sentence.

While that was the longest to date to come from special counsel Robert Mueller’s probe, it could have been much worse for Manafort. Sentencing guidelines called for a 20-year-term, effectively a life sentence for the 69-year-old.

Manafort still faces the possibility of additional time from his sentencing in a separate case in the District of Columbia, where he pleaded guilty to charges related to illegal lobbying.

Before Judge TS Ellis III imposed the sentence, Manafort told him that “saying I feel humiliated and ashamed would be a gross understatement”. But he offered no explicit apology, something Ellis noted before issuing his sentence.

Manafort steered Trump’s election efforts during crucial months of the 2016 campaign as Russia allegedly sought to meddle in the election through hacking of Democratic email accounts. He was among the first Trump associates charged in the Mueller investigation and has been a high-profile defendant.

But the charges against Manafort were unrelated to his work on the campaign or the focus of Mueller’s investigation: whether the Trump campaign coordinated with Russians.

A jury last year convicted Manafort on eight counts, concluding that he hid from the Internal Revenue Service (IRS) millions of dollars he earned from his work in Ukraine.

Manafort’s lawyers argued their client had engaged in what amounted to a routine tax evasion case, and cited numerous past sentences in which defendants had hidden millions from the IRS and served less than a year in prison.

‘Absolutely no evidence’

Prosecutors said Manafort’s conduct was egregious, but Ellis ultimately agreed more with defence attorneys. “These guidelines are quite high,” Ellis said.

Neither prosecutors nor defence attorneys had requested a particular sentence length in their sentencing memoranda, but prosecutors had urged a “significant” sentence.

Outside the court, Manafort’s lawyer, Kevin Downing, said his client accepted responsibility for his conduct “and there was absolutely no evidence that Mr Manafort was involved in any collusion with the government of Russia.”

Prosecutors left the court without making any comment.

Though Manafort hasn’t faced charges related to collusion, he has been seen as one of the most pivotal figures in the Mueller investigation.

Prosecutors, for instance, have scrutinised his relationship with Konstantin Kilimnik, a business associate US authorities say is tied to Russian intelligence, and have described a furtive meeting the men had in August 2016 as cutting to the heart of the investigation.

Defence lawyers had argued that Manafort would never have been charged if it were not for Mueller’s probe. At the outset of the trial, even Ellis agreed with that assessment, suggesting Manafort was being prosecuted only to pressure him to “sing” against Trump.

Prosecutors said the Manafort investigation preceded Mueller’s appointment.

Bruce Fein, a former justice department official, called Thursday’s prison sentence “exceptionally lenient”.

“The judge has a reputation for disliking special counsels. He thinks they target people and then look for crimes, rather than the other way around,” Fein told Al Jazeera.

“I think you could detect some of his disdain for some of the prosecution itself, where he would interject comments suggesting that he didn’t think certain things had anything to do with Russian collusion – why was the special counsel going after Mr Manafort for things unrelated to Russian collusion.”