[FACT] "THE BEST WAY TO REACT WHEN SOMEONE IS SHOUTING AT YOU IN ANGER"

If you are sure you are in no physical danger, don't do anything.
Don't move.
Don't speak.
Don't nod.
Don't break eye contact.
Wait it out.

Sooner or later the shouter will realize that he/she is getting no where and will say something like, 'Well, aren't you going to say anything?'
Your response at this point should be, 'Not until you are calm'.  Full stop.

If the shouting resumes, simply remain impassive until it ends, no matter how long it takes.

Refusing to 'feed' someone's anger will result in them deflating a lot sooner than if you attempt to rebut or appease.

If they stomp out in anger, let them go.
Don't bring up the situation later.
Let them do so if they choose, but once again, refuse to engage with them unless and until they are ready to discuss with you in a calm respectful manner.