The person is repeating what is quoted in the UK.If you research the history of the Pekin Bantam , you will read many stories about their origin.Some say that they were stolen in the 1800’s from a private collection of the Emperor of China, in Peking. Others say that they were imported as a gift to Queen Victoria the early victorian era. The birds from those bygone days were then bred, by keepers in the UK, crossed with other breeds of Bantams to create what we now know as the Pekin Bantam. Some people say that Pekins are known around the world as Miniature Cochins or Cochin Bantams, but it is generally agreed in the UK, by fanciers and keepers, that they are in fact a true Bantam and are not related to or connected to Cochins.
Now for the USA history. The Bantam Cochin and the Large Fowl Cochins have been recognized as breeds by the APA since the 1870's. The ABA has recognized Bantam Cochins as a breed since the ABA was organized. Each has their own standard that they are measured against. That is a history of breeding to a standard for almost 150 years. So in a historical sense the person who told you this may have some merit. I will bite my tongue and not go any further on the information given you. Any more specific questions please PM me.
Craig