excoriate

I think I may have found an error in the Random House Dictionary. While reading '1215 The Year of the Magna Carta' I came upon a word I wasn't exactly sure of, "excoriate". I looked this up on dictionary.com and was given a Random House Pronunciation Key - Show Spelled Pronunciation[ik-skawr-ee-eyt, -skohr-] Pronunciation Key - Show IPA Pronunciation
–verb (used with object), -at‧ed, -at‧ing.
1.
to denounce or berate severely; flay verbally: He was excoriated for his mistakes.
2.
to strip off or remove the skin from: Her palms were excoriated by the hard labor of shoveling.
[Origin: 1375–1425; late ME < style="FONT-VARIANT: small-caps" href="http://dictionary.reference.com/search?q=ex-">ex-1]
Dictionary.com Unabridged (v 1.0.1)Based on the Random House Unabridged Dictionary, © Random House, Inc. 2006.
This is all fine and dandy except the origin is cited as being from 1375-1425. The source in the book is Tristan, which was written in the mid 1100's.
I tried writing RandomHouse on their website to account for this discrepency of dates, but could not find an email address that I could send mail to.
One of the slowest books I've ever read, the exact name of which escapes me, but the subject
being the creation of the Oxford English Dictionary describes the process of creating what is considered the foremost dictionary. The dictionary took like 80 years to complete. It contains either 400,000 or 600,000 words. (Why is it that when estimating we always estimate by evens or odds?) Anyway, many people basically sent in definitions to the dictionary on words they knew. This was back before computers and shit. They basically had a bunch of shelfs with buttfuckin tons of words shuffled in there. It was an arduous process, but created a good dictionary.