Yes I was wondering about that myself. He did seem slightly vague on that point in the video. His exact words were (2:45)
This seemed a little unclear to me. At first when he said "protein food" I thought perhaps he was talking about per ounce of whole food, but then at the end of the sentence he says "per ounce of protein", suggesting that it really is per ounce of just the protein content itself.
So my question to you Robert is: Are you certain about what he meant there, or are you also guessing? Because I am somewhat unsure.