How to know if DONATION is inter vivos? Mortis causa?

An action was filed to recover property claiming that purchase of it from Casimiro Vere was on July 1971, who had earlier bought it from Alvegia Rodrigo in August 1970. Answer was filed, claiming that said property was purchased from Eufracia Rodriguez to whom Rodrigo donated in May 1965. The deed of donation stated among others:

[1] a property was given to the done, his heirs and successors;
[2] the Deed of Donation or that ownership be vested on her upon my demise.
[3] if the Donee predeceases me, the same land will not be reverted to the Donor, but will be inherited by the heirs of EUFRACIA RODRIGUEZ;
[4]f The done accepted the land donated;
Is this donation one mortis causa or inter vivos? Reason.

It is immediately apparent that Rodrigo passed naked title to Rodriguez under a perfected donation inter vivos. First. Rodrigo stipulated that “if the Donee predeceases me, the [Property] will not be reverted to the Donor, but will be inherited by the heirs of x x x Rodriguez." This signals the irrevocability of the passage of title to Rodriguez’s estate, waiving Rodrigo’s right to reclaim title.

This transfer of title was perfected the moment Rodrigo learned of Rodriguez’s acceptance of the disposition (Art. 734, NCC) which, being reflected in the Deed, took place on the day of its execution on 3 May 1965. Rodrigo’s acceptance of the transfer underscores its essence as a gift in presenti, not in futuro, as only donations inter vivos need acceptance by the recipient. Indeed, had Rodrigo wished to retain full title over the property, she could have easily stipulated, as the testator did in another case, that “the donor, may transfer, sell, or encumber to any person or entity the properties here donated x x x” or used words to that effect. Instead, Rodrigo expressly waived title over the Property in case Rodriguez predeceases her. (G.R. No. 172804)