As the climax of Murray's manslaughter trial looms, Dr Paul White maintained his belief that Jackson caused his own death by injecting propofol, but conceded that the medic's actions were risky.
"I would have done things differently in terms of calling for help and calling 911," said White, who repeatedly clashed with prosecutor David Walgren, and at one stage was admonished by the judge.
The trial has heard that Murray did not call 911 immediately on finding Jackson lifeless in the bedroom at his Los Angeles mansion, after spending the night trying in vain to help Jackson to get to sleep.
The medic, who says he had left the room for only two minutes, instead began giving cardiopulmonary resuscitation (CPR) before calling Jackson's personal assistant, who called a guard, who eventually called 911 some 20 minutes later.
White also conceded that Murray could have lied when he failed to tell paramedics and emergency room doctors about having given propofol in the hours before Jackson's death on June 25, 2009.
"I think it was something that he overlooked," he said initially, before being repeatedly questioned by Walgren over whether Murray could have been lying. "It's an option, yes," he said.
In addition he acknowledged that propofol is usually used only in a hospital-like setting, and not normally in a patient's bedroom. "Without careful bedside monitoring, it could be dangerous," he said.
The heated exchanges came as the involuntary manslaughter trial resumed, entering its final act after five weeks of testimony about how exactly the star died in June 2009.
Walgren launched his cross-examination by quizzing White about details including whether it was wrong for Murray not to have kept detailed medical records of his care for Jackson.
He also notably asked how much White had been paid for giving testimony in defense of Murray. The respected anesthesiologist said he had so far been paid $11,000, but that he expected to receive more.
At one point judge Michael Pastor asked the jury to leave the court, before admonishing White -- who added that he usually was paid $3,500 a day for court testimony -- and ordering him simply to answer Walgren's questions.
"I don't like it, it's not going to happen again," the angry judge said.
A short time later White mentioned in open court -- with jurors present -- to the fact that the judge had asked him not to refer to certain things -- prompting Pastor to fine him $1,000 for contempt of court.
After White's testimony, the prosecution and defense are expected to give their closing arguments, before the seven-man, five-woman jury retires to consider its verdict.
While many observers have difficulty seeing how Murray can escape a guilty verdict after four weeks of relentless prosecution testimony, the defense will hope to make a final appeal to sway the decision its way.
Murray faces up to four years in jail if convicted of involuntary manslaughter over Jackson's death from "acute propofol intoxication" in Los Angeles, where the singer was rehearsing for a series of planned comeback shows.
The prosecution claims that Murray, who was being paid $150,000 (105,000 euros) a month, killed Jackson by administering a deadly cocktail of drugs to help him sleep, and then abandoning him at the crucial moment.
The defense has sought to present Jackson as a desperate drug addict, who would have ended up killing himself with an accidental overdose with or without Murray's help.