Cardiologist Alon Steinberg criticized Dr. Conrad Murray on Wednesday, saying the personal physician to late pop star Michael Jackson should never have left him alone.

Prosecutors say Murray, who has been charged with involuntary manslaughter, negligently gave Jackson a lethal dose of propofol, a surgical anesthetic.

Murray’s defense team says Jackson injected himself the propofol dose that killed him.

“When you monitor a patient, you never leave his side, especially after giving propofol," Steinberg said. "It's like leaving a baby sleeping on your kitchen countertop. You would never do it because there's a small — a very, very small — chance that the baby could fall or grab a knife or something."

Nader Kamangar, an internsive care and sleep medicine specialist was also critical of Murray’s departure from the room without an assistant nearby.

“Fundamental basics of the Hippocratic oath, or the ethics and morals that physicians swear by, is to do what's right for your patient, not to abandon your patient," Kamangar said.