Reservista or reservatario?

Reserva troncal is a convoluted subject. This much is admitted by Prof. Ruben Balane in the opening paragraph of his essay Reserva Troncal: Prospect and Retrospect:

The essay is available for download here.

It is no wonder that Paras mixes up the reservista and the reservatario. On page  330 of the book Civil Code of the Philippines, Annotated, Vol III, 2013 Edition we have this paragraph:

The quoted jurisprudence confirms that Paras interchanged the terms:

This decree having become final, all persons (appellees included) are bared (sic) thereby from contesting the existence of the constituent elements of the reserva. The only requisites for the passing of the title from the reservista to the appellee are: (1) the death of the reservista; and (2) the fact that the reservatario has survived the reservista. Both facts are admitted, and their existence is nowhere questioned.

One additional point: we can do away with requisite number 1. It is a surplusage (a favorite word of a law book author whom I could not remember at the moment).