After Wolverine and the kids with him are picked up from Bobby's house, they have to dodge two missiles fired at them by fighter jets. During the excitement, Wolverine reveals a curious tendency to sound Australian while yelling. If it was one line I'd let it go, but he slips from Canadian to Australian for the duration of the flight.
i dont know if this really counts. hugh jackman who play wolverine is an aussie. so im thinking he slips in to his normal accent without realizing it or anyone else.