It shouldn't be difficult to measure the height of the fairing from a fixed point on the frame on each side to determine if the fairing is mounted straight or not. The more likely source of the disparity is the fact the instrument cluster is mounted to the bars/fork brackets, not the fairing, and the angle changes as the bars are moved. Prove it to yourself by swinging the bars from left to right and back again while watching that fairing to cluster gap. You might need to look at the alignment of the bars when the bike is tracking straight down the road to see if they are "tweaked" a bit to one side. Of course if it's aligned perfectly when the wheel is aligned straight, that doesn't mean it's going to stay that way while riding on a crowned road.
Jerry