Why would you be so combative? Wouldn't you grant the interviewer the benefit of the doubt and describe the most recent three things you can talk about? Is the question somehow offensive?
If someone asks me today specifically for the most recent three things I have invented, I am not going to lie in my answer. I am going to explain why I can not disclose any of those three and ask if they would rather hear about ones I can disclose. That you see this response, which is correct, true and factual, as "combative" shows that you have a problem.
In fact, your response to the parent was fairly combative as well. Instead of pointing out a problem in the parents point you have instead tried to find fault in the parents character.
Firstly, your first answer is a direct parry to the question. Whilst factual, it doesn't assume good faith of the interviewer, that they would be happy to hear about three recent things that you can talk about. I think you are on the wrong side of the line between the principle of quality and the principle of quantity -- you mention it would be lying not to talk about the literal three most recent, but I don't think most people would interpret it that way.
You then make what could easily be interpreted as a boast in relation to the multiple patents you hold. This is not a directly aggressive statement, but it is an offensive move in the status game you are playing with the interviewer. I wouldn't say it is the wrong thing to say; but it might be the wrong time to say it.
You then riposte with a reasonable question, but given you just slammed their question and asked them to clarify, it is unfortunate to then ask another question, basically forcing them to decide whether to mollify you or continue their own questioning.
Finally, you make another powerful status signalling move. Think of it this way -- if the people are impressed by these signals, they want to hire you already so why are you even having an interview? Therefore, chances are this interview is for someone else's benefit (HR or management) and neither of those groups will respond well to your attempt to take high status.
It's not a bad answer, it could certainly work well in some circumstances, obviously it could come across differently in actual conversation, but as it appeared it is combative.
I recommend reading http://en.wikipedia.org/wiki/Cooperative_principle and http://en.wikipedia.org/wiki/Gricean_maxims.