Los Angeles (CNN) -- Dr. Conrad Murray's defense team challenged the motives and methods of the prosecution's anesthesiology expert Friday, while the judge threatened to hold the defense propofol expert in contempt for comments he made about the prosecution. Dr. Steven Shafer, the last prosecution witness, will still be on the witness stand when the trial resumes Monday. Shafer testified Thursday that the "only scenario" to explain Michael Jackson's death was that he overdosed on propofol infused through an IV drip set up by Dr. Murray. Prosecutors argue that Murray's reckless use of the surgical anesthetic propofol to help Jackson sleep led to his death, while the defense contends Jackson self-administered the fatal dose, along with sedatives, without Murray knowing.
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NEW: Defense anesthesiology expert faces a contempt of court hearing
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NEW: Dr. Steven Shafer says Michael Jackson could have turned the fatal IV drip on himself
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NEW: If Jackson infused himself with propofol, Dr. Conrad Murray's still guilty, Shafer says
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Murray's involuntary manslaughter trial could to go the jury the end of next week
Shafer demonstrated how he believed @placeholder set up the propofol infusion by hanging a 100-milliliter vial from a stand with tubing attached that would have led to a catheter port in Jackson's left leg.