The only problem with that, Mr. Chairman, is that Mr. Williams might want to hold off the public discussion until you've had an opportunity, if you choose to do this, to hear from the witnesses about the discrepancies.
If you publicly point out the discrepancies and how you find the discrepancies to be worrisome, you're simply offering an opportunity to the witness to rehearse subsequent testimony in a way to avoid any accountability. You might want to hear what the explanation is for the discrepancy, and then you might have a public discussion later about the acceptability of this divergence in the testimony.