Sade Anding, of Houston, Texas, was one of 11 people with whom the physician, Conrad Murray, spoke by telephone in the hours leading up to Jackson's shock death on June 25, 2009.
In other testimony at hearings into whether Murray should stand trial for involuntary manslaughter, the court heard that 12 vials of the powerful sedative propofol which killed Jackson were found in a closet at his home.
The waitress said she had met Murray in a Texas steakhouse in February 2009. The pair had exchanged phone numbers, and she received a call from the doctor on the morning of the fateful day.
"He told me that he was doing well," she said, adding she had cut him off and started talking, but realized five or 10 minutes later that Murray was no longer on the phone.
"I heard a commotion... coughing, mumbling of voices," she said, adding that she was unsure if the mumbling was coming from Murray.
Anding said she stayed on the phone for about five minutes, saying it was unusual for Murray to stop responding. "I just remember saying, 'Hello? Hello? Hello? Are you there?' Are you there? Are you there?'" she said.
The waitress eventually hung up and tried to call Murray back and send him text messages, but got no reply.
Prosecutors allege that Murray, 57, negligently administered an overdose of the powerful sedative propofol to help Jackson sleep and then tried to cover it up. The doctor denies the charge of involuntary manslaughter.
Paramedics and emergency room doctors this week have said Murray initially failed to mention having administered propofol, and that Jackson appeared to have died at least 20 minutes before they arrived at his mansion.
On Thursday paramedic Martin Blount said that when he arrived Jackson seemed to have been dead for at least 20 minutes, despite Murray's claim that he had stopped breathing a minute before they were called.
Blount added that Murray initially denied having given Jackson any medications, but said he saw the doctor holding a needle and spotted three bottles of the anesthetic Lidocaine on the floor.
In new evidence Friday coroner's investigator Elissa Fleak said she found 12 vials of propofol in the wake of Jackson's death.
One was found empty on the floor near the singer's bed shortly after his death, while the other 11 were discovered four days later in a closet at his rented home.
Two had been opened and were found inside a dark-blue Costco bag, while the other nine, some of them open, were found in another bag, Fleak said.
Anding meanwhile said she heard nothing more until police contacted her. She called Murray, who apologized for involving her, and urged her to call his lawyer to be present if she met with detectives.
Los Angeles detective Dan Myers told the hearing that Murray had made or received 11 cellphone calls, totaling some 90 minutes of conversations, in the roughly five hours leading up to midday on the fateful day.
These included a 32-minute call to his medical practice in Las Vegas and an 11-minute call shortly before Murray called Jackson's personal assistant at 12:12 pm to say the singer had had a "bad reaction."
Prosecutors allege that Murray "abandoned his patient" after administering the propofol some time between 10:40 am and 11:00 am.
Murray could face up to four years in jail and lose his doctor's license if the case goes to full trial and he is convicted.
Jackson's death shocked the entertainment world and triggered intense debate over the performer's health in the run-up to the London concerts, known as the "This is It" tour.
