Hmm… hard to say with a part like this. For a problem where it seems like the dimensions are off (as opposed to having a bend) I would typically take measurements with calipers along the part in different directions, and compare them to the original model to see if I can find any patterns.
Given the organic shape of your part, however, that would be difficult to do. I can only thing of trying to print some calibration parts in a similar orientation to try to reproduce the problem with an easier-to-measure part.