During cross examination, Deputy District Attorney David Walgren appeared frustrated with the responses he was getting from Dr. Robert Waldman, an addiction expert who is not board certified.
The jury watched Walgren and Waldman go back and forth like they were watching a tennis match, and nervous gasps were heard in the courtroom.
"What do you mean by material?" Waldman asked.
"What do I mean by material?" Walgren started to respond, but was cut off by Waldman who said, "You said material, it's your word."
"Uh, do you know what material means?" Walgren fired back.
"I do. I'm wearing material," Waldman retorted.
That was just one of many testy exchanges between the two. At one point, Walgren stopped his line of questioning to say, "Is there a reason why it's so difficult for you to answer my questions, and it was so easy for you to answer Mr. Chernoff's?"
Waldman began his testimony with discussing the symptoms and signs of addiction, and then later discussed the treatment of addiction.
When lead defense attorney Ed Chernoff began questioning, he displayed Michael Jackson's medical records of injections from Dr. Arnold Klein, a Beverly Hills dermatologist.
The records showed Jackson was given multiple shots of the anti-anxiety medication Midazolam and the opiate Demerol, which is a strong pain medication.
Murray contends that Jackson was addicted to Demerol, which Waldman affirms carries a side effect of insomnia, which could have led to Jackson's craving for the sedative propofol in order to sleep. Murray asserts Jackson overdosed himself, self administering the anesthetic when Murray left his bedside.
Based on the records, Waldman said Klein gave Jackson high doses of Demerol and Midazolam for cosmetic procedures both minor and odd, like Botox for wrinkles and to control sweating in the groin.
One point the records showed was Jackson was given 900 milligrams of Demerol over three days. Waldman told the court that this was a very high dose, and could possibly show that Jackson was addicted.
"I believe there is evidence that he was dependent upon Demerol," Waldman testified.
"What about addicted?" Chernoff asked.
"Possibly," Waldman replied. "Based on my prior definition and what's known about his public behavior, and this course of treatment, that he was probably addicted to opiates."
The prosecution reminded jurors that no Demerol was found in Jackson's body at autopsy, and also pointed out that Waldman's opinion was based on flawed and incomplete information. Under cross examination, Waldman backed away from his earlier claim.
"Dr. Waldman, would you diagnose Michael Jackson as addicted to Demerol based strictly on these documents in my hand, yes or no?" Walgren asked.
"Probably not," Waldman testified.
The final defense witness is Dr. Paul White, who is undisputedly the most important witness for the defense. The propofol expert is expected to resume his testimony when court resumes on Friday morning.
The prosecution will then take the weekend to review evidence and then cross-examine White on Monday.
White and Dr. Steven Shafer, the prosecution's propofol expert, were colleagues, but Shafer was very critical of Murray for giving Jackson propofol in a home setting.
White could be facing contempt of court charges for comments he made to the media about Shafer, and he reportedly called Walgren a "scumbag."
Superior Court Judge Michael Pastor set a hearing for Nov. 16 for possible sanctions against White.
Outside the presence of the jury, Pastor advised Murray of his constitutional rights to take the stand in his own defense if he chooses to do so. A decision must be made this week.Murray is on trial for involuntary manslaughter for Jackson's sudden death on June 25, 2009, at the age of 50. Prosecutors allege Murray tried to hide the fact that he had been giving propofol to Jackson.
Murray, 58, has pleaded not guilty and has denied any wrongdoing. If convicted, he could face up to four years in prison and lose his medical license.
The trial is expected to last five weeks, with Oct. 28 being the estimated last day.
View photos from the involuntary manslaughter trial of Conrad Murray.
