Mrs. M, you were right to ignore the pathetic individual in question. He seesaws in and out of his medications, I would imagine, varying between being truly helpful/productive and being the complete jerk that he apparently is. I have always suspected emotional disturbance in his case. Why else would he take such great pleasure in hurting others, even to the point of researching ancient posts to do so?
He is a sad specimen of humanity, and his irritations are not worth your valuable time. Please do ignore him and perhaps one day he will learn to conduct himself respectfully, especially where his elders are concerned.