He was having an argument with his girlfriend, "involving a lot of profanity", and then when Singapore Airlines flight attendents did not serve him alcoholic beverages, he became more unruly.
A Darwin court was told that Donovan told twice a flight attendant, "Do you want to take me on?"
SQ0235 has 298 passengers (92% load factor) and 14 crew on board. It landed in BNE two and a half hours late at 0900.
Singapore Airlines spokesman Stephen Forshaw said that the airline had incurred approximately A$25 000 / US$17012.50
"In this case, the captain has made an assessment that this man's behaviour warranted the aircraft making an unscheduled landing into Darwin so he could be dealt with by authorities. There is no room for tolerance of unruly behaviour on aircraft. Singapore Airlines and its crew will now cooperate fully with the authorities to ensure they have sufficient information to bring the matter before the courts expeditiously."
"These decisions are not taken lightly; they are expensive, but more importantly, they represent a serious inconvenience to other customers. But the captain's primary focus was the safety and welfare of his passengers and crew, and his decision was necessary for that reason."
Singapore Airlines Pte Limited apologises for any inconvenience caused to customers.
"There were no complaints from passengers about the decision to put down in Darwin and get rid of this guy. In fact, when he was led off the aircraft by police, the police were cheered."
More information at the Reuters / Yahoo website, the Ninemsn Australia website and the Sydney Morning Hearld website