I can see that the aim of my question is rather far from the article content. However, I am just a surgeon, and the question is quite important in both practical and scientific point of view. Having much references browsed, I can not find a reliable answer.
Besides, you found that not less than 5% of the liver tissues studied contain the exocrine pancreatic tissue (which to some extent resembles that of teleost fish liver) [Terada T, Nakanuma Y, Kakita A. / Pathologic observations of intrahepatic peribiliary glands in 1,000 consecutive autopsy livers: Hetero-
topic pancreas in the liver // Gastroenterology 1990; 98: 1333-1337]. So, if you do not mind, my second question goes forth:
Why does the pancreatic juice inside intrahepatic bile ducts remains harmful and does not cause the chronic cholangitis, or something of the kind?
Article What are ductal plate and ductal plate malformations of human livers?