I think basic logic is that Cassidy Hutchinson's testimony is hearsay. I don't think its a stretch to say when stories and accounts are told,and retold they are dramatized and embellished.
Her testimony isn't hearsay.
You can argue that she offered nothing but hearsay evidence that Trump grabbed the steering wheel.
Since, of course, whether or not he grabbed the steering wheel is irrelevant to any major point, why do you care?
Like I said - because that is salacious, the MSM is going to latch onto it. Also, because it was an anecdote about what someone told her, it is the bit the RW will challenge, which gives the MSM their chance to make the focus a "who is right about the steering wheel" argument, which helps Trump and crew.