If you wait, it replays it with the action zoomed in. If you click "play again," it makes you watch a different video, which I think is good, because you don't want to be too keyed in on a single instance.
You're right. I hadn't noticed that because the text popped up and I scrolled down to read it. That happens early in the video, and there's more video of people not drowning. So I scrolled up to try and replay the video, tried to seek back to the start, failed, then clicked on the YouTube logo.
I'm sure I could have noticed it, but somehow I didn't. Mostly, but perhaps not entirely, my fault.