But he did push it in post, and that contributed to the noise. Even though it wasn't much, when you expose to the bottom part of the range in raw mode the camera is really sensitive (that's why its DR is better than other cameras in it's price range). It's also why exposing to the right within reason (95% clipping on brightest spot), gets you the most control over your image.
ETTR and clipping are two different things. You should never clip.
JG, the most sensible point in the DR (as you said) for the BMCC is always going to be the least sensitive region (the right), such that you do not clip.