I think part of your problem here is that your response, which you said was comparable to the initial "insult", looked absolutely nothing like the initial "insult". And everything that you described as being in the initial "insult" just plain wasn't there. You may have thought certain things were implied, but even if you are correct, that still isn't the same as saying them outright like you did. I'm not sure if you are aware of that or are incapable of distinguishing or why, but whatever is causing it, the fact is that you are the one doing the overt insulting and flaming.
Indeed, youth as a cause of gullibility (among other behavioral issues) would be a
compassionate explanation of your behavior. Implying you may be too young to think clearly isn't insulting because it is the
nicer of the options. So I disagree with origin saying refusal to answer implies you are young. Since not being young is worse (ie, if you are older, you should know better; if you are younger it is ok not to), I think not answering implies you are old enough to know better.
Also, it is important to note that not all logical fallacies are always actual fallacies. Ad Populum and argument from authority are fallacies only if abused. If used correctly, they are logically valid. Look at it from the other direction: in order for the one who stands alone to be correct, he has to be the smartest person in the group. Is that likely?
See:
http://philosophy.lander.edu/logic/popular.html
Science utilizes ad populum and the related appeal to authority: expert opinions matter more and the accepted correct answer is a matter of consensus (majority decision).