If you look at the tweets involved, they checked with Carson’s staff. They were told he was going to Florida. Since the CNN report was what equated that to quitting, Cruz apologized for his staff member(s) making the wrong conclusion. Carson did better than he was polling; did this really hurt him?
The CNN on air report did not equate it to quitting. They said he was taking a break, said it was unusual, but never said he was quitting.
Carson did better than he was polling; did this really hurt him?
Irrelevant. So did Cruz. Does not mean he stole votes from Carson? Polls for the Iowa caucus are generally less accurate than polls for primaries.