If the exact segmentation of the source sentence was known, then the model could have used the information that the word gaadi {car} appears in a segment whose head is the noun chaalak {driver} and hence its not unusual to put gaadi {car} before bola {said} (because the construct "NP said" is not unusual).
since the segmentation of the source sentence is not known in advance, we use a heuristic (explained later) to find the segmentation induced by a reordering.