The report says one witness saw the wings level before impact. Glendalegoon and Slatch you are correct with your drill.
The other possibility could be a runaway engine on the right side which can give the sense in the pedals of failure on the left. You have to double confirm on the Torque gauges as to what you have. I have 2000hrs + on older King air 90s and we had to brief the runaway engine scenario before each takeoff. Of course the B90s I flew were a lot older than this 1999 B200 with smaller engines with Fuel Topping governors ( which were notorious to failure) etc.
My condolences to the victims and families.