Parole evidence

I was reading page 50 of The Insurance Code of the Philippines Annotated, 2010 Edition by De Leon when I saw this:

I learned about parol evidence in first year law. So this must be a minor typo by De Leon. But it was there again on the next page:

So I checked the case law referred to by the book which is American Home Assurance Company vs. Tantuco Enterprises, GR 138941, October 8, 2001. Indeed the term used is parole evidence. A search through the Philippine Report Online brings up 40 decisions using the term parole evidence.

However, it seems parol evidence is still the prevalent usage in Philippine jurisprudence.

How about in American jurisprudence? A quick search through the Chan Roble website reveals no usage of "parole evidence".  In fact, according to Bess Hambleton in her Legal Solutions Blog  "parole"  is  wrong spelling when used with "evidence":

So why is it that 40 or more Supreme Court decisions use "parole evidence" instead of "parol evidence?"

Could it be that the ponentes felt awkward using parol because parol conjures the image of something else among Filipinos [as in here]?

Seriously, however, there is a basis for the use of parole in Philippine jurisprudence. Parol evidence, as we learned, refers to oral evidence. In first year law I used to ask myself why the roundabout way from parol to oral; why not poral evidence?

The world parole is actually related to oral. Parole comes from French and refers to spoken words. See here. Therefore, the usage is not reversible error on the part of the ponentes.