What would you do in my shoes?

If you didn't say anything rude to someone,(Let's call them person A) you simply corrected them on a couple of things, and they (Person A) said "This video is what I have to say to you" https://youtu.be/BXUhfoUJjuQ then what would you/person B (The one person A is talking to) do? And how should you/person B respond to something so crude and unnecessarily mean?
The reason I ask this is because I was browsing the forums when I came across this: http://smilebasicsource.com/forum?ftid=1268 Some user called Necro studios was saying that to someother user called good gamer god.
This is me: http://smilebasicsource.com/user/Hiiii I'm having email issues so I can't register my account yet, but I was bullied a lot in school and I hate to see bulling outside of school and on the internet...
So it got me thinking: What would you do in my shoes? Would you intervene? Or if you were in his shoes, what would you say back?
They're both young and annoying. Who cares. The thread will rot in a while. Getting involved gives credit to either of them. If someone doesn't "want to be helped" that's their own fault, and maybe on the part of the person who thought they were helping because really maybe they weren't either.
The way you respond should be based on what you want out of the situation. If you value tranquility, you should just leave it be and remember that some people don't like to be corrected, even if you're just trying to help. If you value justice, you can tell them what you think they did wrong and prepare for the inevitable argument.