LOS ANGELES, Calif. (KTLA) -- An expert reviewer from the Medical Board of California told the jury Wednesday that Dr. Conrad Murray's care of Michael Jackson leading up to his death was so inadequate that it violated the Hippocratic oath, an ethical promise doctors make to do no harm.

Dr. Nader Kamangar, a physician specializing in pulmonary critical care and sleep medicine, said in a report for the medical board that Murray's care included several extreme mistakes. His testimony echoed that of another doctor -- a cardiologist -- who took the stand earlier in the day.

Kamangar called the decision to give Jackson the powerful anesthetic propofol outside a hospital setting "inconceivable."

"In this case it was clear there was a period of time when Mr. Jackson was basically left alone and was not being monitored. That in somebody that is receiving sedation is really not acceptable."

Also on Wednesday, attorneys for Murray told the judge they were dropping their claim that Jackson swallowed propofol when Murray was out of the room.

The defense still is arguing that the singer could have injected himself with an extra, fatal dose on June 25, 2009.

Murray has admitted giving the 50-year-old Jackson 25 milligrams of propofol.

With the jury out of the courtroom on Wednesday, Murray's attorneys and prosecutors presented medical studies to the judge that have shown propofol has no major effects on a person when swallowed.

Dr. Alon Steinberg, a cardiologist who reviewed Murray's treatment of Jackson for the California medical board, said even if the singer administered propofol to himself, the physician still would be responsible for his death.

"It's like leaving a baby that's sleeping on your kitchen countertop," Steinberg said. "You look at it and it's probably going to be OK and you're just going to go grab some diapers or go to the bathroom but you would never do it."

Steinberg said Murray displayed six "extreme deviations" from the generally accepted standard of care.

Those were: Administering propofol for sleep when it is meant for anesthesia; giving it at a home instead of a medical facility; not being prepared for an emergency with enough staff and equipment on hand; not taking the proper measures to revive Jackson when the singer stopped breathing; not immediately calling for an ambulance; and not keeping proper records.

"If these deviations hadn't happened, Mr. Jackson would have been alive," Steinberg said.

Steinberg and Murray are both cardiologists. Steinberg's findings were relied upon by the California medical board earlier this year when it suspended Murray's doctor's license.

"I've never heard of anyone using propofol for sleep except Dr. Murray," Steinberg said.

Murray, who has pleaded not guilty to involuntary manslaughter, faces up to four years in prison if convicted.