In reply to:

revenge/reciprocate

No, of course he isn't right. They don't mean quite the same thing. Reciprocate has meanings fairly close to revenge, but it also has others not so close. What does he think a reciprocating engine does? This is the peculiarity of the English language -- it has an enormous number of words, many of which mean exactly, or almost exactly the same as another, but more often with not quite the same, the differences in meaning often being very subtle.