I suppose you could make a dumber statement, but it is hard to imagine how.

Can you explain how anyone could know that or why it is even important to know that? Of course you can't. There is ample evidence  that Oswald was in the sniper's nest at 12:30 firing the shots that killed JFK. The fact you think it is important to know where Oswald was in the minutes leading up to the assassination reveals just how dumb you rare.

Nobody could have a rational debate with someone as stupid as you. You think the most trivial things are important while ignoring the compelling evidence that Oswald was the assassin. That is not an assumption. An assumption is a belief made in lieu of evidence, such as all theories that anyone except Oswald took part in the crime. The fact that you obsess over trivialities such as a supposed elevator race prior to the assassination reveals just how clueless you are. You focus on all the dumb stuff while ignoring what is important. Sorry, just being honest.

You still don't get it and you never will. Witness estimates regarding time frames don't establish anything because they are nothing more than guesses.

As usual, the moment you try to engage with this subject you end up looking buffoonish. Your lack of knowledge regarding the basics of this case is ridiculous.
Norman states that he and Junior Jarman decided to go up to the 5th floor after hearing that the motorcade was on Main Street:

MR. NORMAN. Well, we stayed there I believe until we got the news that the motorcade was coming down, let's see, is that Commerce, no Main, because Commerce- we went beck in the building, James Jarman and I.

The motorcade joins Main Street at Harwood Street and it is a matter of a few minutes before the motorcade reaches Dealey Plaza. When we look at the transcripts of the police radio transmissions we find that the earliest mention of Main Street is around 12:22pm.
This is not a guess.
Norman timestamps their decision to go up to the 5th floor with his reference to the motorcade being on Main Street.

You are so pitifully stupid that you think every word of testimony the WC heard over the course of the investigation should have been included in the report

It would be kind to call this statement 'moronic'.
'Devious' would be a better description.
The point I'm making, as I'm sure you are aware, is that your precious Warren Commission Sham left specifically left out any testimony or statement that ,contradicted the false narrative they created with the insertion of Givens' false account of going back up to the 6th floor and seeing Oswald. This is beyond dispute which is why you have to resort to such crass misrepresentations. You are incapable of providing any kind of rational excuse for the WC's actions. You have to resort to lies and misrepresentations instead. It's really weak-minded.

What the hell difference does it make what time BRW joined Norman and Jarman

You really do need to be spoon fed, don't you?
If BRW didn't go down to the 5th floor until 12:25pm or later, it leaves no time for Oswald to assemble the rifle in the SN as your precious WC Sham would like everyone to believe.
The problem the Sham faced was that there is no time for Oswald to assemble the rifle before BRW was on the 6th floor and not time for him to assemble the rifle after BRW has left the 6th floor. They had to create a false narrative to give Oswald time to do this before BRW was in position.
So they invented the nonsense about Givens going back up to the 6th floor and seeing Oswald near the southeast corner. The importance of this lie was having Oswald refusing to go down to the first floor. This gave him time to prepare the SN and assemble his rifle.
But the testimony and statements of Williams, Givens, Lovelady, Arce and Piper told a very different story - Oswald was looking to get down to the first floor but Givens refused to stop and let him on the elevator. So Oswald called down to them to send the elevator back up to him so he could come down. Whether he got the elevator or not is unknown but what we do know is that he did indeed get down to the first floor, as his interaction with Piper proved.
In reality, Oswald was down on the first floor around 12:00 noon, approximately the same time BRW was arriving at the 6th floor where he would stay until at least 12:25pm.

The plaid bars and Lovelady's visible bald spot are not doctored...Neither is Shelley's Duck's Bahookie hair doo, black jacket, and white shirt collar...This is why the corruption on The Education Forum is so wickedly evil...Because it poisons and harms the phony academic standard that website pretends to uphold...Mark Knight is like a dirty small town sheriff who always does the job he's expected to do with his rulings and avoids recognizing the dishonest corruption of the people he's ruling in favor of...The membership pretends to avoid it as well...Simkin then puts on that phony Oxford/Cambridge above it all intellectual act and skates past the issue that he is fully responsible for as if he doesn't notice...The current Couch/Darnell film is good enough for any credible researcher to realize the pair fast-walking up the extension are already long proven to be Shelley and Lovelady and that anyone doubting it is basically trolling and marring good progress of research...The Education Forum refuses to answer for the correct evidence on Prayer Man that proves Prayer Man is Sarah Stanton...This one thing alone discredits all the self-platitudes they assign themselves as far as credibility...

The Education Forum gets away with the murder of switching the issue from the rotten dishonesty of Sandy Larsen and his deletion of evidence that disproved himself to a witch-hunt against the researcher who single-handedly out-argued the board on its favorite pet theory...The dishonest scoundrel who pushed that theory (Bart Kamp) is now safely a member while he still hasn't admitted the obvious evidence that refuted him...Mark Knight has been allowed to disappear the entire issue by means of bullying and vindictive moderation disguised as high-minded academic moderation and ban the person with the correct evidence for life on trumped-up BS designed to protect the wrong-doers...Knight is not made to answer for how his wrongful moderation has prevented exposure of the most important evidence discovery of our generation nor is that very important discovery ever shown on the forum...Jim DiEugenio is shilled and pampered by a membership that honors his taking a theory that he already admitted to me was false and bringing it to Congress...This dubious process endangers the credibility of JFK Assassination research - but that doesn't bother Jim D because he is an entity that always manages to get bailed out by his own wordsmithing and the corrupt sycophants who always endorse it...This is all capped-off by the ultimate insult to injury of Andrew Iler having total power and pretending he has addressed all this with a dignified set of rules, when all he is is just another Jim DiEugenio butt-******...There has to be someone on The Education Forum who remembers Larsen's photo analysis of Lovelady's plaid bars...The main thrust of that forum is not good research...It is organized dishonesty and may they be damned for it...