There was no CNN report. During some live coverage, a couple talking heads were musing about how odd it was that Carson was going to Florida and commenting that it didn't seem like the actions of someone who was planning on pursuing a serious campaign. The Cruz campaign then tweeted that CNN had reported that Carson was dropping out, which was not the case.
The fact that the Cruz campaign has since fired a couple staffers for similar incidents tells me that they had some unscrupulous people working for the campaign.