Maybe I am out of touch with modern operating practice, but, in my day a loco immediately in rear of a failed train could be called forward to propel the demic to the next point where the train could be put away.
By putting the loco in front of the train, it would be required to return to the failure wrong road, possibly over several blocks. More realistically it would return to the failure on the other line before either going behind to propel, or being allowed wrong road over the last block to draw the failure out. Either way, to me a longer procedure.