It is not.
1. No Secret Service agent had stated up to that point that her testimony - that she heard this story on that day - was false. Links to articles with unnamed sources with unvalidated access saying that secret service agents saying that she was correct that Trump wanted to lead the attack on the Capital himself, but that he didn't try to grab the wheel
are not statements by secret service agents that her testimony that she heard this story on that day is untruthful.
2. The Secret Service itself had released a statement only that its agents were - contrary to your claims that they couldn't testify - fully cooperating and available to testify. The Secret Service as an organization
also did not say that her testimony - that she herd this story on that day - was false.
She was not with Trump during the supposed altercation.
And she has not claimed to be, mentioning only - in the middle of quite a lot of other testimony - that she heard this particular story of this particular anecdote, in the context of Trump wanting
to lead the attack by people whom he knew to be armed on the Capital. The man was trying to stop the peaceful transfer of power and overturn our representative system of government - whether or not in the course of that he attempted to
grab a wheel is perhaps a colorful, but, ultimately, not incredibly relevant detail.
That is why she is telling the story third had (she is testifying to what she says one agent told was told to them by an agent on the scene),
Engels was - according to the sworn testimony, which is the evidence that we have at the moment - standing next to Ornato when he told this story, and said nothing to contradict it. Do you have something saying that Ornato was not in the vehicle, and would have gotten this story from Engels?
I'll ask you this: If any of the agents actually testified to the occurrence, why would the committee rely on third hand testimony?
Because the molehill that is being focused on is not the mountain. The story here isn't "OMG TRUMP TRIED TO GRAB A WHEEL", it's "Holy Shit, He Legitimately Wanted What Almost Happened To Happen, Because He Thought He Could Keep A Hold Of Power"
I'll ask you this: The Committee
has the sworn testimony of the agents. If they knew that her story was crap, why would they put her up there and have her tell it?
Also, why is every quote by this "witness" prefaced by statements like "he said something like"?
Well, when all you read is her accounts of conversations that she had, you are going to get a lot of that.
Mostly Partisan. There are Republicans there, but, chosen more to give the appearance than the substance.
Who is there to cross examine these "witnesses" on behalf of the Trump administration?
Well, Republicans could have chosen to participate and do so, but, decided not to, because Pelosi wouldn't let them put Jim Jordan on the committee to spend all day trying to sink it. So, they had the option - just not with the lead guy they wanted - and chose not to take it.
The investigation would be made a lot stronger if they did have that - it's not a fatal flaw, but it is a major one.
The evidence that they did not is the simple fact that the committee had to rely on third hand hearsay rather than callup an actual witness.
If anything - while not being evidence - that is suggestive that they knew that the agents testimony largely at least lined up with hers. According to the same unnamed sources with unvalidated access that you are claiming as evidence against he wheel driving anecdote, that is, in fact, what happened - and the agents confirmed that Trump wanted to lead an armed mob in an assault on the capital.