"Senator McCain was absent from the hearing due to a scheduling error," McCain spokesman Brian Rogers told ABC News.
Even if he had attended, McCain was unlikely to be satisfied with what he heard.
There are currently at least four Senate Committees looking into the Benghazi attack. For her part, Sen. Collins does not agree with McCain's call to combine those into one special - or "select" - committee like the one that investigated Watergate.
" I do not see the benefit of, nor the need for a select committee," Collins said. "Our committee, our Homeland Security Committee has government-wide jurisdiction and a history of producing comprehensive bipartisan reports on everything from the Ft. Hood terrorist attack to Hurricane Katrina, so I don't see the need for creating a brand new select committee to take a look at this."