Is Cardinal Trujillo right about excommunication for deliberate embryo destruction?

Canon Lawyer Edward Peters takes a look at the question:

Alfonso Cardinal Lopez Trujillo, the outspoken president of the Pontifical Council on the Family, has asserted that "destroying human embryos is equivalent to abortion"; therefore, he says, those directly involved in such deeds are liable to the canonical penalty established for abortion, namely, excommunication (1983 CIC 1398). That the cardinal stands on solid biological and moral grounds in equating deliberate embryo destruction with procured abortion is beyond serious question. What I want to ask is whether he stands on solid canonical grounds as well.

Consider: until the last few decades, all canonical discussions of abortion were concerned with actions occurring, obviously, within the womb. The recent development of extra-uterine fertilization technologies, however, including cryogenic storage of embryonic human beings, has created a group of humans at peril for their lives, but who, given the canonical maxim that penal laws are subject to narrow interpretation (1983 CIC 18), might fall outside the scope of the traditional abortion canon. So, one must ask: is the deliberate destruction of an embryonic human being outside the womb the canonical equivalent of an abortion procured within it?

Cardinal Lopez Trujillo believes that it is, and I think he's right. How? [More...]