That theory will likely be a question that defense attorneys will ask Los Angeles jurors to ponder at the involuntary manslaughter trial of Dr. Conrad Murray, which is scheduled to begin March 24.
Murray plead not guilty to the felony charge last month.
In a police affidavit it said that Dr. Murray told police Jackson craved propofol to treat his insomnia and that he referred to the drug as his "milk."
According to anesthesiologist Dr. Barry Friedberg, who last month met with one of Murray's defense attorneys to be screened as a possible expert witness, Murray's lawyers will argue that "Jackson could have swallowed propofol" himself. (Monday is the deadline for both the defense and prosecution to present their witness list for the trial.)
Friedberg says there appears to be a small amount of evidence to support the defense's theory. For instance, he says there were traces of the drug in Jackson's digestive system, which could have gotten there from drinking the sedative.
However, he says, it's the doctor's responsibility to create a "safe environment" by carefully monitoring a patient's breathing.
A Question of Safety"I'm curious as to how "safe" Dr. Friedberg thinks a doctor must be to prevent a patient from injecting himself or drinking a drug when he leaves the room," lead defense attorney Ed Chernoff tells PEOPLE.
During the preliminary hearing, prosecution witness Dr. Richard Ruffalo conceded under cross examination that, upon closer scrutiny of the coroner's toxicology report, it appeared plausible that Jackson "self-ingested" some of the propofol, as opposed to Dr. Murray administering all of the drug to Jackson.
The pop star's father, Joe Jackson, was furious over the suggestion that his son, while preparing for one of the biggest tours of his long career, caused his own death.
"That's bull––," Joe said. "It's not possible that Michael would do that. The whole family knows – and Michael's fans all over the world know – that this is not true. It's a lie. We're outraged about it."
With reporting by CHAMP CLARK