Dr. Stephen Brown was in charge of the department from 2006 to 2010, but told the court "there was very little direct supervision" of the 25 doctors under him.
One of the those doctors, George Doodnaught, is charged with 21 counts of sexual assault. Twenty of the assaults are alleged to have taken place in the operating rooms in the hospital. Another in a private clinic.
Doodnaught, 64, has pleaded not guilty to all charges. He worked at the hospital from 1981 until his arrest in 2010.
Brown testified Thursday that Doodnaught would have filled out a reappointment form every year.
When Doodnaught completed his form for 2009 he ticked off a box stating he had never been the subject of any hospital investigations regarding his conduct.
Brown testified that he signed off on that form, affirming Doodnaught's good standing.
But earlier evidence given at the trial shows that by 2009 the hospital already knew of two complaints against Doodnaught.
More women later came forward after Doodnaught was arrested in 2010, to say they too had been sexually assaulted while undergoing surgical procedures in the operating room.
In many cases the women claim Doodnaught kissed them, fondled their breasts and commited other sex acts while they were sedated — but conscious — and with other doctors and nurses just a few steps away.
The trial continues.