There have been many posts about seat reclining, and I've never seen consensus achieved as to whether reclining is fair or unfair.

First, that the incident took place prior to takeoff is not really relevant, since I don't think you would have felt much better about the man's irritable reproof of you for hitting the back of his seat had it occurred at a different time, say during the main course of the flight. So in my view this is less a question of justice, of who was rude or more accurately, of who was in the right, than it is of how to handle the inevitable irritable passenger whom one will meet on an airplane, be it in economy or business class.

As you no doubt know, airline staff are not infrequently the focus of attacks such as the one you received from your irritable co-passenger. The staff I admire most are those that resist the urge to defend themselves, even and perhaps especially when the attacker is in the wrong. I note that these staff seem to be most effective when they express sympathy with the passenger's emotions, if not the passenger's take on the situation ("I can appreciate how frustrated you must be, sir....") Especially in a situation where there is little either of you can do (you cannot change the spacing of the seating, and with or without reclining, seat knocks are a fact of life in economy), sometimes just listening and sympathizing with a person calms them down, and perhaps can make you feel better too.