Further, we need to be hammering the point that the response about never having felt pressured is a deflection.
He needs to be asked, under oath, "did the president inquire with you about intervening in an ongoing investigation?"

It's a yes or no question, and it requires an actual answer, not a diversion.

After all, he doesn't need to protect his job.

That whole hearing was bullshit and contempt of Congress

Sadly, I don't expect much out of Burr, but Warner should file contempt charges and subpoena their asses

they confirmed Trump's inappropriate requests. Just the way they squirmed on the uncomfortable hot seat was revealing

As long as said person hasn't previously has a discussion about conversations with the President.

If the had, you are spot on in your assumption.

It could be concern for their own legal jeopardy in the matter or it could be they're afraid of they answer they'll be pulled into the investigation too.

One thing that is fairly certain, their non-answers probably put them on Mueller's radar.