I have heard that the rudder trim was found set hard left, FWIW.
There was a 310 out of Tamworth in 2005 that got airborne and rolled over on its back with an obvious outcome. It took the ATSB a while to work that out but eventually they come to the conclusion that it had come out of the hangar with the rudder trim set full left. The pilot was to ferry it to Scone and was in a rush so missed the trim part of the checklist. If the trim on the Kingair was full left then it would go a long way to explain the flight path. If the pilot thought he had suffered an engine failure but the engines were producing power then there is too little time available to do any trouble shooting.