In his defense, I'm sure a number of people, back in early February, thought that Puerto Rico's delegates would all go to one candidate, though probably for different reasons.
It's not hard to look up the DNC delegate allocation rules before writing something publicly.
Did he actually say it would be winner-take-all? If so, he's an idiot.
But, what I was trying to say was, I'm sure most back in February thought that by Puerto Rico we'd have a nominee and that nominee would win all the island's delegates and super-delegates.