There are two ways if that doesn't happen:
1. Refutation is fake.
2. Refutation is true, but the refuters aren't called in.
Well, as i said, and as Andrew Mccarthy pointed out, there are larger issues at stake.
However, I do believe the committee should put any one up publicly, televised, under oath, if they have contradictory testimony. I think they are obligated to since they televised Hutchinson. But I'm not in charge.
AS to fake refutation... that's why I won't trust fully trust Ornato. He is a political appointee. I suspect you don't get there without being all-in Trumper. Engle is also suspect. I doubt you get his position as a Never-Trumper.
There is supposedly an unnamed SS driver who was present. That is the testimony I want. It's possible you don't get on Trump's detail at all without being a true believer, but I'm willing to wager that a low level agent, under oath, testifying televised in front of the Congress of the United States is going to decide to be completely honest.
But as Mccarthy pointed out, this is a minor question compared to the other issues.