thanks i understand shutter opening and i see what you are saying. The motion blur can make the track look off, but the track is still correct.
I'd be interested to see the difference with some tracked footage. usually you matchmove something to place an object on the ground etc, so this fast motion MB shouldn't really apply to this situation... unless the camera is moving really fast.
if its an object track (sort of like the phones in your example but talking 3d not 2d.) i can see how this would effect it greatly.

i think we ought to see the shot to know what it is.