The Grammy-winning record producer shook his head repeatedly under questioning before a jury as an attorney described Francis' accusations, which Jones called fiction.
Francis says Jones told him that Wynn had threatened to hit him over the head with a shovel and have him buried in the desert. Francis also says Jones showed him a stack of emails supposedly detailing the threats. Francis said under oath that Jones told him Wynn was a gangster and "old Vegas."
"That sounds like a line from 'Scarface,'" Jones said. He added that he would like to see the emails Francis claims he displayed.
Francis acknowledges he never read the emails and didn't ask Jones, who is his next-door neighbor, to let him read them.
Wynn has vehemently denied he ever threatened Francis. Wynn has testified that Francis' comments are damaging to his reputation and could hurt business at his Las Vegas resorts, the Wynn and Encore.
He told jurors Tuesday that he had never sent an email in his life, and Jones said he hadn't ever seen one sent by Wynn.
Jones was one of the final witnesses in a three-day trial that has given jurors some insight into how Las Vegas works, administratively at least.
The trial has also featured testimony about Francis' messy legal troubles, which have included being jailed in Florida and later in Nevada on tax evasion allegations.
Jones has played a prominent role in both Wynn and Francis' lives, maintaining a close friendship with the casino boss for more than 35 years and attempting to bail Francis out of a Florida jail several years ago.
Wynn's attorney Barry Langberg asked multiple questions about Francis' accusations. Jones alternated between appearing taken aback by the statements attributed to him to smiling and shaking his head. "Absolutely not," he repeatedly said when Langberg asked about whether Wynn had ever conveyed a threat toward Francis.
Jones said he attempted to mediate a dispute between Francis and Wynn's casino over $2 million in gambling losses.
"I was trying to just make peace," Jones said, adding that he wanted Francis to "do what he should have done in the first place."
"If you lose the money, you pay the money," Jones said. "That's ridiculous."
Jones has won multiple Grammy awards for his work with artists such as Michael Jackson and the superstar 1985 collaboration "We Are the World."
He was initially a reluctant witness, citing doctor's orders for why he was unable to testify during the case. He said he wasn't really feeling well after taking the witness stand Thursday morning, but laughed and cracked several jokes while testifying.
When asked about Francis and their relationship, Jones said he tried to bail his neighbor out of a Panama City, Fla., jail after he was arrested on suspicion of filming underage girls. Jones said he had traveled to Mexico and the Middle East with Francis for events, but acknowledged it could be a lot of work at times.
"A lot of drama," Jones said of Francis.
Closing arguments in the case will begin Friday.
Anthony McCartney can be reached at http://twitter.com/mccartneyAP