The Way to Handle Confliction with Boss at Work

One day, one of my colleague at work was pissed off because boss did something disrespect to him and was yelling at him in front of other people while they were talking something else together in his office. He did not say anything when this happened and he did something to fix the problem which made boss angry. After that, he thought over and over and felt unfair about this thing.

He wrote this letter below to let boss know what he feel:

I dig out this email which I had been told last time what needs to be changed for the branch 
coop approve interface. I modified the interface the exact way you told me to change, 
the url link, folder directory and encrypted the order number.We did have a quick talk 
about this too. What I remembered is that you wanted the interface is as simple as possible 
and you never say anything about the web page at all.  At that time, it seemed that 
the new Sun Life web site will be launched soon and this interface waits until the new 
Sun Life web is switched over. Since then, I have not been told anything about this. 
I guess we all forgot this. Also, for the quite long time, I do not report to you directly 
because Foo (another sucker name) is in the middle. If there is something I understood wrong, 
please let me know in person. I had a very tough day today. I send you this email because I am 
unhappy what happened today, the way you yelled at me, especially in front of quite a few 
other people in my office. I am nice and patient but not to this extend.
I did learn my lesson from this. From now on, I will send every single task you tell me to do 
as my record. Also I will back up my emails every 3 months in case something is deleted permanently.
I need a talk about this whenever you have time. 

Thanks,

Sad Man

The next day, early morning, boss called him and they had a talk about thing happened.Boss said sorry to him and explained what and why this thing made him so angry that he could not hold his temple.
Boss said he did not mean to hurt his feeling and he has been doing great job.
He is one of my best friends in the company and he told me about the whole thing and the way he handle this problem.

We have to stand up for ourselves when disrespect or unfair things happened at work. Do not be afraid of boss and do not sweat at work!

This is what I learned from this.