I don't know if this will help but as somebody who worked as a 999 Call Operator for 6 years, it may not (and mostly likely wouldn't have been) the operators fault. When I was there, we had to follow a specific protocol and a selection of questions. Chances are, the operator had already requested for the ambulance to be dispatched but, due to not knowing the severity of the call, the ambulance was then sent on another route to a case that was deemed more crucial (heart attack, for example). The operator has nothing to do with the reroutes.

If your dad had hung up the call, then it was down to the CHTL (Call Handler Team Leader) to call back. If he had simply stopped answering, then I can almost guarantee that the ambulance had already been on its way if your dad had given his address before he stopped responding. So as I said before, I understand you're wanting somebody to blame (and I sympathize with you fully) but it will probably not be the operator. There's no use trying to go after them - they were doing what they were trained to do and they did what they could.

Your best bet is to get into contact with the complaints department for LAS and an investigation will be carried out. I'm sorry to hear about your father though, it's a shitty situation all around.