It is very relevant as the first two versions of events did not include Brewer at all. Therefore, he may not have been in a position to see anything. Your lack of knowledge of the evidence doesn't make me a kook.
Where is the word "punch"? Where is the name "McDonald"? Remember according to McDonald he was the one grabbing LHO.
The name 'McDonald' is in the part of Brewer's testimony that you conveniently left out.
John Calvin Brewer WC Testimony
http://mcadams.posc.mu.edu/russ/testimony/brewer_j.htm(...)
BREWER - Well, I saw this policeman approach Oswald, and Oswald stood up and I heard some hollering. I don't know exactly what he said, and this man hit Patrolman McDonald.
Mr. BELIN - You say this man hit Patrolman McDonald. Did you know it was Patrolman McDonald?
Mr. BREWER - I didn't know his name, but I had seen him quite a few times around Oak Cliff. But I didn't know his name.
Mr. BELIN - Then you later found out this was Patrolman McDonald?
Mr. BREWER - Yes.
Mr. BELIN - Did you say this man was the same man?
Mr. BREWER - The same man that had stood in my lobby that I followed to the show.
Mr. BELIN - Who hit who first?
Mr. BREWER - Oswald hit McDonald first, and he knocked him to the seat.
Mr. BELIN - Who knocked who?
Mr. BREWER - He knocked McDonald down. McDonald fell against one of the seats. And then real quick he was back up.
(...)