NBC Nightly News anchor Brian Williams was a guest last night on CBS' Late Show with David Letterman, and the pair discussed the botched swearing in.

Williams described it as "Harvard vs. Harvard," and had a theory as to why there may have been some tension between President Barack Obama and Chief Justice John Roberts.

"For the first time in American history, this was a chief justice swearing in a president who had voted against his confirmation," said Williams. "So, here we have your natural tension."

Williams wasn't the only NBC'er to appear on the Tiffany Network last night — Chris Matthews was a guest on The Late, Late Show with Craig Ferguson.

Click continued to see a clip of the Williams interview...