Parasitology ping
The worm obviously did not come from bacon. Bacon is processed, cured, smoked and cooked.
My bet is that Rosemary is an illegal, and ate the pork in Mexico, or they are eating meat from feral hogs.
Pork from the modern commercial hog farms is parasite free and completely safe to eat. Pork from Mexico or from feral hogs is not parasite free or safe to eat if not cooked to the point of being vulcanized.