I think that turning back was the only option in the circumstances. As the report says the woman sustained a head injury and was also seen by a Doctor on board. Regardless of the state on intoxication of the woman, the fact she may have injured her head in a fall could have proven more serious later if the flight had continued. I’m sure that any Doctor would recommend further investigation as soon as possible and that no Airline Captain would want to risk carrying, potentially a seriously ill patient. Imagine what the press would have said if the aircraft continued and the woman died. Best to be cautious don’t you think.