Prosecutors in the child molestation trial called Bob Jones, Jackson's former publicist, to the stand to testify about an alleged incident on a flight from Paris to Los Angeles.
They wanted Jones to testify that Jackson licked the boy's head to show a pattern of behavior. Jackson is alleged to have licked the head of his current accuser on a flight from Miami to Santa Barbara in February 2003.
But when asked if he had seen Jackson lick the boy, Jones responded, "No, sir."
Prosecutor Gordon Auchincloss then asked whether Jones had said during an interview with Auchincloss, Jones' attorney and a sheriff's investigator that he may have seen Jackson lick the boy's head.
"I was very adamant in saying I was not sure," Jones said. "I don't recall anything about licking. ... I don't recall ever seeing any head licking."
Jones was only the most recent prosecution witness to testify differently than prosecutors had hoped.
Previously, Jackson's former house manager testified as a prosecution witness that he had brought wine and soda to Jackson and several boys. Witness Jesus Salas had only told investigators that he brought wine, but said on the stand that he just remembered the sodas.
Jones said he had observed some other physical contact between Jackson and the boy, who received a multimillion-dollar settlement after accusing the pop star of molestation and subsequently declined to participate in a law enforcement investigation of that case.
Jones said that at the World Music Awards in Monaco the boy sat on Jackson's lap and the boy's sister also sat on the singer's lap for a time. He characterized Jackson and the boy as inseparable during the trip and said that on the flight back they huddled closely together as they slept.
Auchincloss then read an excerpt from a book Jones is writing about his experiences with Jackson.
"They were holding each other tightly, almost in a romantic sense," Auchincloss quoted from the book, which also said Jackson and the boy were cooing and kissing and that Jackson licked the boy's head.
Auchincloss asked Jones whether the passage in the book was accurate.
"Yes, with reservations," Jones said.
When the defense objected to several questions, Auchincloss said he was asking for the sake of impeachment.
On cross-examination by Jackson attorney Thomas Mesereau Jr., Jones testified that his co-writer completes passages of the book and that he then checks them for accuracy.
Jones said that he had not yet reviewed the section Auchincloss read in court and that it was not accurate.
Mesereau also noted that Jones had not been sworn to tell the truth when working on the book.
"When you were dealing with your co-writer and publisher you were not under oath, and of course today you are," Mesereau said.
Prosecutors are presenting witnesses from Jackson's past to show he has a pattern of inappropriate behavior with boys and to help the credibility of his current accuser.
Jackson, 46, is accused of molesting a 13-year-old former cancer patient, plying the boy with alcohol, and holding his family captive in February and March 2003 to get them to help rebut a damaging documentary.
On Sunday, Jackson's mother issued a statement explaining her reasons for leaving the courtroom during testimony Thursday.
Katherine Jackson, who has been present for every day of her son's child molestation trial, said many media outlets misinterpreted her absence from the courtroom as a reaction to testimony. She said she left to use the bathroom.
"I am only asking for fair and accurate reporting," she said in a statement released by a family spokeswoman. "Accusing me of leaving due to graphic testimony when I simply went to the rest room is not fair, not accurate."
The Associated Press did not report on her absence from court.