The idea of a lawyer who starts arguing against his own case may sound like a character from a bad sitcom, but it occurred at least once in real life. The biography for Lord Eldon relates that when he was young, and simply known as John Scott, he was working as a junior to Mr Dunning (“who was the most eminent of the counsel prectising in the Court of King’s Bench”).
The anecdote, as told by Lord Eldon, goes:
“He began the argument, and appeared to me to be reasoning very powerfully against our client. Waiting till I was quite convinced that he had mistaken for what party he was retained, I then touched his arm, and, upon his turning his head towards me, I whispered to him that he must have misunderstood for whom he was employed, as he was reasoning against our client. He gave me a very rough and rude reprimand for not having sooner set him right,”
Yet Mr Dunning managed to get out of this situation with a very elegant solution...
“[He] then proceeded to state, that what he had addressed to the court was all that could be stated against his client, and that he had put the case as unfavourably as possible against him, in order that the court might see how very satisfactorily the case against him could be answered; and, accordingly, very powerfully answered what he had before stated.”
Twiss, H. (1844) “The Public and Private Life of Lord Chancellor Eldon” Vol 1, p63