Firstly.. yes, he sounds like an arse, and had it coming.
But I am going to slightly push back on the idea that they are the same, and it is a fair comparison. Yes, both are about size, and yes both can relate to a preference...
But there are also differences that make it a bit less fair.
Penises are much more essential to the success of sex. Breasts don't determine whether a man "feels" anything or not, whereas size/shape/ED issues directly impact what a woman feels. Hence why men can get far more depressed about it...
Equally, Women tend to support other women, and there is a societal pushback against shaming women for the size of their chest. Imagine going to a group of women and saying "My husband said a bad comment about my small chest!!" - you will get sympathy (as in this thread) and get told that plenty of men love smaller chests.
But if a man came to a group of men and said "My wife made a bad comment for the size of my small cock!!!" - he will get teased, humiliated and laughed at by the other men (and women) around him. No one will say "hey mate, look its fine, there are plenty of women who love small dicks."
Also, lets be 100% honest, there are plenty of men who like smaller tits... but are there really women who openly declare their love for small cocks? I've known men who are full of admiration for smaller breasts, but I've never met a women who openly goes looking for small cocks...
However, in the other direction. Breasts are far more visable/open, whereas men can "hide" their size in public.. so that would be an area where pensies are actually less sensitive as a topic.
So, yes he had it coming, and yes it was fully deserved.. but no in general, I don't think they are entirely fair comparisons. and the insecurity and worry on both sides is a bit different.