"The modern Colorado River did not carve the Grand Canyon in the last few million years," Dr. Elston said. "The canyon was already there."
This is an odd thing to quote in support of the view that the Grand Canyon was carved in a few weeks. Out of context, it's difficult to tell what this Dr. Elston was talking about. In context, it has nothing to do with the Grand Canyon being carved in a few weeks.
The quote comes from
this article on a website offering Grand Canyon tours, who say it's originally from the NYT. Elston is quoted as defending the traditional view that the canyon was carved out slowly between 60 to 75 million years ago; against more popular modern hypotheses that believe it all happened within the last 5 million years.
Of the various geologists quoted in the article, none advances a view at all resembling the idea that the canyon was carved in months, though it does mention that some support the idea of "a catastrophic flood that carved the Grand Canyon very quickly,
within a couple million years" (emphasis added).