Over here at Letters of Note is a reprint of Scottish poet Robert Burns's 1791 reply a critic:
Dear Sir:
Thou eunuch of language; thou Englishman, who never was south the Tweed; thou servile echo of fashionable barbarisms; thou quack, vending the nostrums of empirical elocution; thou marriage-maker between vowels and consonants, on the Gretna-green of caprice; thou cobler, botching the flimsy socks of bombast oratory; thou blacksmith, hammering the rivets of absurdity; thou butcher, embruing thy hands in the bowels of orthography; thou arch-heretic in pronunciation; thou pitch-pipe of affected emphasis; thou carpenter, mortising the awkward joints of jarring sentences; thou squeaking dissonance of cadence; thou pimp of gender; thou Lyon Herald to silly etymology; thou antipode of grammar; thou executioner of construction; thou brood of the speech-distracting builders of the Tower of Babel; thou lingual confusion worse confounded; thou scape-gallows from the land of syntax; thou scavenger of mood and tense; thou murderous accoucheur of infant learning; thou ignis fatuus, misleading the steps of benighted ignorance; thou pickle-herring in the puppet-show of nonsense; thou faithful recorder of barbarous idiom; thou persecutor of syllabication; thou baleful meteor, foretelling and facilitating the rapid approach of Nox and Erebus.
Source:The Works of Robert Burns, Vol. 4.
Are there other examples from the legal academy of expressive rejoinders as witty as this one by Burns? The Martha Nussbaum v. Stanley Fish dust-up from the mid-1980's doesn't come close. Other contenders?