Tagalog Goof???????

Someone stated (in the Goofs) that the use of Tagalog in the Lingayen Gulf was a goof... It is true that that region speaks Pangasinan but they also speak Iloco, Bolinao, Tagalog and English. I can't be sure how much Tagalog and English were spoken there in the 1940's though,,, if the film were to be historically accurate... And,,, in the credits,, it says that this was filmed in the Bicol region,,, where they speak Bikol, Albayano, Masbateño, Rinconada, Pandan Bikol, Sorsoganon, Tagalog and English... Since the Lingayen Gulf is on the west coast (central) part of Luzon and Bicol is at the extreme southern end of Luzon,,, it is understandable that Pangasinan is not spoken.