I’ve tried paddle-boarding. As a beginner, its REALLY hard to get one’s balance and stand up. It means you fall into the water A LOT
So the chef was either a strong swimmer because he would have spent a lot of time in the water constantly trying to get back on the board.
OR it was extremely stupid to take a non-swimmer paddle-boarding. Its difficult to believe.
He was learning to swim as an adult. He was not very good at it (I've watched the video of him in the pool. He can barely swim with flippers on).
He got overconfident and decided to go paddleboarding. Lots of folks drown when they go out on the water despite being marginal swimmers.