"Why can't the dressing be changed in the hospital?"

My father had surgery at The Avenue Hospital in Melbourne. He required a change of the dressing including a new backslab and this was arranged to happen in the private rooms of his surgeon that is approximately 200m away, across a suburban street. The hospital staff asked my elderly mother to take him in a wheelchair across the road for this appointment. She lives quite a distance from the hospital and when she told hospital staff that she couldn't push the wheelchair because of a chronic back problem, they insisted she find someone else to take him. Finally she had to change the appointment time and take her teenage grandchildren to the hospital to take my father across the road. I am disappointed that a) the hospital could not arrange to have the dressing and backslab change done on site at the hospital and b) they could not arrange transport. I am curious to know where liability stood if something had happened to my father on the public road while he was an inpatient at The Avenue hospital and being transported by a child? ?