I understand the older brother's anxiety when he understood that he is far inferior to his younger brother even though he, as the older one, was raised as the heir. With that high expectation, he will unconsciously have this feeling that being an heir is his sole purpose of life, it is what he is. So the fact that the younger brother is better than him, it might "erase" him as a person. So he unconsciously feels his existence is threatened.
But to actually drop his younger brother like that...He needs to do much more than just an apology...
@WhoCares Agreed. I do hope they can at least somewhat go back to talking and not ignore each other.