Superior Court Judge Yvette Palazuelos did not immediately finalize the ruling after hearing more than two hours of arguments from lawyers.
A jury in October rejected Katherine Jackson's lawsuit claiming AEG Live LLC negligently hired the doctor convicted of giving her son an overdose of anesthetic in 2009.
Her lawyers argued the verdict form didn't allow jurors to fully consider evidence in the case. Lawyers for AEG Live countered that there was no basis for a new trial.
AEG Live attorney Jessica Stebbins Bina told the judge it was actually Katherine Jackson's lawyers who included the disputed language in drafts of the verdict form and instructions.
Jackson family attorney Deborah Chang, however, said the question that brought jurors to end the case couldn't have been corrected and should have been excluded from the form.
Palazuelos did not indicate when she would finalize her ruling. If she stands by it, Katherine Jackson's attorneys could pursue an appeal with a higher state court.
Jurors heard more than five months of evidence in the lawsuit trial.
Katherine Jackson sued AEG Live on behalf of herself and her son's three children, accusing the concert promoter of hiring Dr.
Murray, who was deeply in debt, expected to be paid $150,000 a month to care for Jackson while the singer prepared for a planned series of comeback concerts in London's O2 Arena. Jackson died on June 25, 2009, after receiving an overdose of propofol, which Murray was giving Jackson as a sleep aid.
Murray was convicted of involuntary manslaughter in 2011 and released in October after serving two years in jail.
The trial offered a close look into Jackson's personal life as well as his routines as an entertainer and medical treatments for a variety of ailments.
Jurors later said their verdict did not mean they thought Murray was ethical in his care of Jackson, but that he was fit and competent to serve as his doctor.
AEG Live denied any wrongdoing throughout the trial and said there was no way executives could have known that Murray was giving Jackson propofol in the bedroom of his rented mansion.
Anthony McCartney can be reached at http://twitter.com/mccartneyAP