Los Angeles - The claim that Michael Jackson could have self-injected enough propofol to kill himself was a "crazy scenario", the last prosecution witness at the trial of the pop icon's doctor said on Thursday.
Anaesthesiologist Steven Shafer added that Jackson, who died of acute propofol intoxication, must have had much more of the powerful sedative in his system than the 25mg which accused doctor Conrad Murray admitted giving him.
Murray's lawyers, who started the five-week manslaughter trial claiming that Jackson could have caused his own death by self-administering propofol, said last week they would no longer claim he could have drunk it.
But they have left open the possibility that the star, suffering from chronic insomnia and desperate for rest after a sleepless night, self-injected it via an intravenous (IV) drip in his leg while Murray was out of the room.
"People don't just wake up from anaesthesia hell bent to pick up a syringe and pump it into the IV," Shafer said on Thursday, adding: "It's a crazy scenario."
"Michael Jackson received more than 25 milligrams" of the drug, he added.
Shafer was the last witness for the prosecution in the five-week trial, which began on September 27. After him the defence is due to call witnesses, possibly as early as Friday, and could finish presenting its case next week.
The anaesthesiologist said on Wednesday that Murray behaved like the pop star's obedient "employee" and not his doctor, granting his every request for drugs which led to his death.
In court again on Thursday he questioned a claim by Murray's team that Jackson took eight tablets of the anti-anxiety medicine lorazepam in the hours leading up to his death on June 25 2009.
A defence study had miscalculated the amount of lorazepam by not taking into account a metabolite created in the liver, he said. There was actually a "rather trivial amount of lorazepam", a tiny fraction of a 2mg tablet.
Murray, who was looking after Jackson as he rehearsed for a series of comeback concerts in London when the singer died, claims he was only out of the room for two minutes when he returned to find the singer not breathing.
He is accused of involuntary manslaughter. If convicted, the 58-year-old Murray faces up to four years in prison.