May I point out none of this proves Andrew Mitchell didn't say it. It only proves a so called witness now admits he lied. IMO A. M. did say it . The term 'pleb ' was/ still is meaningless to the majority of the population. How likely is it that an ordinary copper would make it up. He might have said f..... b......s but ' plebs ' ! No way.
I was asked only today by an educated friend what it meant . I don't wish to offend but I would bet many ABers would have difficulty in explaining its meaning and origin.